Diploma in Executive Coaching & Organisational Development (AADCT) 2022-23

Founded in April 2008, our Diploma is the first and longest standing coaching training in Greece. In April 2022, our training enters its 15th, consecutive intake. Featuring a carefully selected faculty of expert facilitators, counting over 170 influential alumni and spanning 120 hours of top-quality training, in 2014, it was globally the first course to receive Accreditation from the Association for Coaching; at top-tier level 4/4. In 2021, our Accreditation was renewed by the Association for a further 3 years.

We have been entrusted with transforming leaders from companies and organisations such as Abbvie, Accenture, ALBA, AstraZeneca, BAT, BDO, Beauty Nova, Carell S.A., Center for Democracy, Cognity, DHL, DMG Mori, Evolution Dojo, Eletson, Elval, Fweebi, Great Place to Work, Information Society, Innora, Jewish Community of Athens, Knowledge Training and Consulting, Microsoft, Mondelez, Nike, OTE Academy, PM Partners, Pharmathen, Rigips, Starbucks, Star Channel, Simply Burgers, S & B, Stoiximan, SC Johnson, Unilever, Vestas, Wyeth, 1Source – Aero Services – as well as several consultants, entrepreneurs, journalists, publishers, mental health professionals, lawyers, project managers, football coaches, martial art instructors and other leaders of transformation.

The Corona Virus challenge has enabled us to evolve and full provisions have been made in order to run every module either on a web platform or live at our host, OTE Academy, subject to the Covid-19 circumstances.

Course Accreditation:

  • In November 2014 our training program became the first to be awarded Accreditation by the Association for Coaching, globally.
  • The Diploma is accredited at level 4/4, Accredited Advanced Diploma in Coach Training (AADCT), which is the top tier. In 2021, our Accreditation was reviewed and renewed by the Association for a further 3 years.
  • The Diploma is awarded by Impact, an Organisational Member of the Association for Coaching.
  • Individual Accreditation can also be obtained upon completing the requested hours of coaching practice and subject to meeting all other application criteria. (Please visit the AC website for more details).
  • Impact can provide supervision towards completing full membership and accreditation requirements.

The course provides 120 hours of Continuous Professional Development Units (CPDU) as indicated on the certificate.


OTE Academy

Lunch, coffee and refreshments inclusive

Full provisions have been made, in order to run every module either on a web platform or live, subject to the Covid-19 circumstances.

Association for Coaching
Accredited advanced diploma in coach training
Entry Requirements

  • Graduate academic qualification and good command of the English language
  • 1 year’s experience in Consulting, HR, Counselling, Management or similar
  • Minimum age requirement 25
  • Personal maturity and capacity to challenge your reflective learning curve

Admission Process

  • Submission of CV
  • Submission of paragraph stating experience & aspirations in coaching and OD
  • Interview with Course Director
  • 50% down payment

We accept an average of 65% of applications received


  1. 3,500 word case study (based on your placement) or research: assessed by the Course Director and/or Facilitators and externally validated if necessary or in case of dispute.
  2. Attendance (85% minimum required) and contribution.
  3. Successful completion of practice/placement and case study presentation (Impact will assist you in finding a voluntary unpaid placement within one of our client companies, but does not guarantee one). The placement entails 3 individual coaching sessions, which will then be presented to the group: Peer Assessed. **
  4. Written examination on theory, covering the core material taught and reading list.***
*Each one of the 4 assessment areas carries equal weight (25%) and must be successfully passed (60%) to secure a certificate
** In addition a 60 hour coaching practice log must be submitted in order to receive the Diploma as required by the Association for Coaching.
***The Graduation/completion rate is approximately 85%, subject to successfully completing and passing all assessment criteria.

Contact info@impactpcs.com or call +30 2108014505 to receive the complete syllabus

Association for Coaching
Accredited advanced diploma in coach training

Vassilis Antonas, Director

Executive Coach, Psychotherapist, Organisational Development Consultant and

Course Director of Impact’s Diploma in Executive Coaching and Organisational Development (AADCT), globally the first Coaching Training to receive Accreditation from the Association for Coaching. Vassilis is the author of Coaching for Impact: The Evolution of Leadership, published by Routledge in 2017.

He has consulted for over 70 Greek and Multinational companies, delivering tens of thousands of consultation hours to leaders from all functions and industries. Clients include Microsoft, Alcon, Nike, NN, Unilever, Mondelez and more.

From 1998 to 2001, he worked for the British NHS and served as Clinical Director for CAP London from 2001 to 2006, at which point he returned to Greece and founded Impact. His vision is to craft the circumstances for pursuing excellence for individuals and organisations: Directly, by offering Executive Coaching and Organisational Development services and indirectly through the Diploma.

Vassilis is also a published song-writer, a martial arts instructor, a free diver, former motorsport driver and devoted world traveller.

Dr. George Diakonikolaou, Associate

George Diakonikolaou is the Managing Director of “Project Management Coach” LTD, delivering services to business clients in the fields of Project Management, Leadership, Coaching and Organisational Development. His clients include companies such as Cosmote, Romtelecom, Vestas, ENEL, EDF etc. George is a visiting Faculty, teaching Project Management in the International MBA in Athens and Brunel Business School, MBA in London as well as Bradford Business School. He has received his First Degree in Electrical Engineering and Computer Science in National Technical University of Athens and his M.Sc. and Ph.D. in Computer Science from University of Manchester Institute of Science and Technology.

George is the co-founder of the Greek Chapter of the Project Management Institute, a Certified Project Management Professional and a founding member of the Hellenic Coaching Association. He is also an NLP Trainer and Master Practitioner of NLP & Time Line Therapy®, a Master Practitioner of Hypnosis and an NLP Master Coach.

Currently, George is experimenting with the integration of Coaching, Organisational Development and Project Management in a field that he likes to refer as “Project Coaching”, an integrated model that achieves groundbreaking results in Strategic Projects, Programs & Portfolios, and executive teams’ performance.

George is a 2010 Diploma Alumnus.

Tereza Venetsanou, Associate

The Founder of Winning Culture and Impact’s Business Development Director, Tereza is a seasoned Executive Coach, Trainer and Organisational Development Consultant. In the past, she has held leadership positions, for over twenty years, in multinational corporations, such as Wind, Vodafone and Microsoft. She is currently also working internationally for Vodafone Group as a Sales Transformation Consultant.

Her qualifications include a BSc in Business Administration, a MSc in Marketing, a Post Graduate Diploma in Executive Coaching and Organisational Development, a Master Practitioner in NLP. In the context of her continuous professional development, she is currently working towards obtaining her MSc in Integrative Counselling and Psychotherapy. Tereza is part of the Assessor’s Team for the Association for Coaching and is currently on her way to securing her Master Executive Coach Accreditation from the same body.

Her combined experience and expertise render her equally capable of coaching senior leaders, training sales teams and optimising the operational and sales structure for small and medium businesses, through on the job mentoring and coaching.

Tereza is a 2019 Diploma alumna.

Katerina Nikoloutsou, Diploma Facilitator (Apodosis)

Executive coach, Music Coach, Europeanist and Master of Education (M.Ed), during the last 25 years, Katerina, has trained thousands of children, adults, people with special needs and professionals. In 2009 she founded Mousiko Parathyro, a Music Coaching Centre in Athens with the mission to explore one’s musical personal self. As an executive coach, she specialises in the use of voice for leaders of any background and the enhancement of their persona.

Katerina is partner in Apodosis Coaching Services and her vision is to give prominence to the fundamental role of voice and one’s self as a tool for development and evolution.

Katerina is a 2017 Diploma Alumna.

Stella Ioannidou, Diploma Facilitator

Stella is a Reskilling Expert who finds joy by driving skilling efforts and strategically managing Change while promoting Engagement, mainly through Talent Management & Learning and Development initiatives. She is also a Senior Faculty Member at the Josh Bersin Academy, facilitating the upskilling efforts of Academy members for the largest HR professional development network in the world. When she is not volunteering as an aspired Executive Coach for Individuals and Start-ups, she blogs about the competencies of Motherhood and how business-relevant they are.

Stella is a polymath, continuously exploring the extents of her knowledge base to sharpen her ability to transfer tools and ideas to enrich her practice: she holds an M.Eng. in Rural & Surveying Engineering and a M.Sc. in Information Systems Management from the National Technical University of Athens, an MBA from ALBA, and currently pursuing her M.A. in Adult Education and Vocational Training. She is a certified Project Manager (PMP®), Agile HR Professional (ICP-AHR), Change Management Practitioner (APMG), and IASSC Certified Green Belt. She practices vulnerability through singing while playing the guitar. She has co-developed Human-Centered Coaching to help foster a world where everyone brings their whole-self to the table.

Stella is a 2015 Diploma Alumna.

Yannis Kanoutos, Diploma Facilitator

Yannis is an all-around facilitator driven by continuous improvement, empathy and story-telling, who loves bringing the human aspect to the way companies operate and to the products & services they offer. He often expresses the belief that technology may be the driver to the design of different products and services, however success still lies on how strongly the human factor is involved and if real needs are met.

He is a certified Change Management professional (APMG) with extensive experience in the Finance industry, especially in the field of Business Analysis (he holds a MSc in Information Systems and he is also IASSC Certified Green Belt). He often contributes as a Coach for Teams that practice human-centred methodologies, since he is a certified Design Thinking facilitator (Dynargie). He is a firm believer in multidisciplinary collaboration and goes about asking teams “why”, as a means to deepen the understanding of needs before addressing challenges.

Yannis’ approach combines a blend of methodologies that maximise a Change’s impact: he draws from a variety of different tools and methodologies and operates as an internal consultant working diligently to shift mindsets and help create impactful product and service offerings.

Jeannette Marshall, Diploma Facilitator

Jeannette Marshall is an AC Accredited Master Executive Coach, has achieved accreditation with the Coaching Academy and has a Diploma in Business Performance Coaching. As Head of Coaching at Marshall Vere Associates and through her work with the AC as former UK Chair and Director of Accreditation, she is passionate about crafting coaching programmes that bring about measurable changes in organisations. Jeannette excels in bringing groups together to focus on a common objective. Her delivery style is highly motivational, charismatic and energetic. Her clients find that their performance, self-motivation and enthusiasm for achieving their goals increases dramatically and often far exceeds their initial expectations.

She provides Executive and Team Coaching services and delivers Training Programmes including: Coach Training Skills for Internal Coaches, Coaching Strategies for Managers, Coaching Strategies for Mentors, Management Performance, Leadership Training, Problem Solving and Presentation Skills.

Course Dates for 2022-23
AprilSaturday 9 + Sunday 10

Vassilis Antonas:
Fundamentals of Executive Coaching & OD
MayFriday 13, Saturday 14 + Sunday 15
Vassilis Antonas:
Transformational Leadership: A Jungian Perspective
The Evolution of Leadership: Leading with PRAID
Coaching for Impact: A Complete Method
JuneFriday 24 + Saturday 25

Vassilis Antonas:
Systems & Organisational Development
Tereza Venetsanou:
Internal Coaching
June to SeptemberStudy Period
SeptemberSaturday 24 + Sunday 25
Jeannette Marshall:
Maximising Self-awareness for Coaches
Coaching Approaches, Tools and Techniques
OctoberSaturday 22 + Sunday 23
George Diakonikolaou:
NLP Coaching for Impact
Katerina Nikoloutsou (Apodosis):
EnhanSing Influence: Τhe Leading voice
NovemberSaturday 12 + Sunday 13

Stella Ioannidou & Yiannis Kanoutos:
Human-Centred Coaching: A Framework
December to January
Placement Delivery, Presentation Design & Thesis Preparation
JanuarySaturday 21 + Sunday 22
Vassilis Antonas:
Placement Presentations
Association for Coaching
Accredited advanced diploma in coach training

Diploma Testimonials 2021-2022

The Diploma has been a truly enlightening experience; one I dare to name a lifechanging one. Once you deeply engage in the process you re-discover yourself and you challenge things and thoughts you took for granted. The process is a collective one. The teammates raise the bar for you; without them the journey would not be the same and would not be a so long one. I do not consider the Diploma to be a training program. It opened doors and paths I wish to further explore so it may very well be the “start” of a journey. A big thanks to Vassilis, Diploma partners and my teammates.
Aris Georgopoulos, Vodafone

Any leader, who is on a path of self-discovery & on a mission for building their coaching presence in pursuit of unlocking potential & accelerating performance of others, should take part in the Coaching for Impact accredited course. This year-long journey will expose you to specific theories and practices needed to develop you into an agent of transformation, be it in context of management coaching or as a professional Executive Coach.
Ali Tahmasebi, Microsoft

I came in with no expectations being open to discover.
What happened though was beyond my greatest expectations! It has been a unique and challenging journey with another 11 fantastic people! Vassilis Antonas has an amazing ability of recruiting people.
I would highly recommend it to anyone who is ready to go deep in his fears, have a transformational experience and take a small step on an never ending journey!
Aikaterini Chaida, NN Hellas

When I applied, I knew this course would not be a typical “coaching” diploma but was not prepared for this deep dive into my self awareness.
Fast forward, 10 months later I can say this was a challenging yet authentic transformational experience- An inward journey where I realized many new ways to perceive, communicate and interact with myself and people around me.
A holistic approach, with experiential learning and a powerful combination of technical and personal skills growth.
Katsali Sofia, KAIZEN GAMING

Have you ever wanted to learn how to influence people? How to be an agent of change for the people around of you? How about learn things that you do not know that you do know? This diploma is the safest environment to be courageous and explore the mechanics of the human psyche starting from yourself and contrasting it with a dozen of other leading executives in the program that aspire to grow and contribute. Needless to say that it’s super fun and you will create deep bonds unlike any other.
Leonidas Karellis, CARELL (www.carell.gr)

A great year in a great course, against all odds posed by the pandemic. The course itself is well designed, the sessions do offer a plethora of insights, the tutors are highly competent, the approach is multi-dimensional, spotlighted by various different angles. But the very essence of it all is the group of carefully selected persons forming the class; it is them, my classmates, all of us together and the group dynamics formed between us, that really enhanced our experience to a “wow” level. My peer group, with whom I embarked on this wonderful journey of knowledge, self-discovery and skillset building, aiming at facilitating individuals and organisations move their way forward. If one aspires to get exposure to top class executive coaching and organizational development consulting, this is the way to go.
Constantine Poulios, Grant Thornton

What a fantastic journey!!!!!!! The Executive Coaching and Organisational Development Diploma was a unique transformational experience. It helped me develop as a person and as a professional, and the application of the course material to my everyday life was immediate and valuable. I would recommend it to professionals that seek to challenge themselves and their limits. Go for it.
Marilena Pappas

An amazing experience! Extremely positive, not only in helping me to identify, frame and clarify key personal development objectives but also offering practical tools, techniques and suggestions to achieve them!
The Diploma empowered me to clearly identify the areas on which to focus, in order to bring the greatest benefit to my personal and professional development.
Sophia Saravanou

This was a challenging journey deep into my mind and soul; powerful, exhaustive yet revealing and rewarding.
Grateful to Vassilis and the whole Impact!
Even more grateful to my peer coaches, the 2022 class!!
George Apostolopoulos, Robit Plc

Being part of this training has been an eye-opening experience. I appreciated the fact that I familiarized myself with disciplines, theories and frameworks that were not known to me and can potentially have a profound impact on my professional and personal life alike. The mix of people was refreshing and the discussions were thought provoking. This is definitely a non-effortless training, it requires commitment and investment of time and mental capacity. To gain the most out of it, you have to step out of your comfort zone and leave any preexisting expectations out of the door.
Mary Bina, Microsoft Hellas

That Diploma was a transcendental experience for me. It helped me understand better the depth of human behavior and the methodology of coaching not as a simple toolkit but as a lived experience of a team that was very carefully selected.
Vassilis Antonas and impact team have put together excellent content that will resonate with professionals that want to challenge themselves and want to make the next step, digging deeper in various areas. That program became a great opportunity for self-reflection and pivotal action. It can definitely help professionals shift in a rather unexpected way, as long as they are ready to let go and immerse themselves in the great content of Impact Diploma. It’s one of those times that I want to do the course again and again.
Dionisis Zacharopoulos, Beauty Nova

To view a full list of our testimonials click here