Meandrou 15, Athens 115 28
+30 210 7292365

About Us

Who we are and what we seek.

THESIS in its almost 40-year course, seeks to support significant business efforts and at the same time to highlight the value of its people. At the core of the value services it offers, is the creation of a trust framework where customers and executives seek and create sustainable solutions from a financial and administrative point of view.

Our scientific training and our professional experience, combined with the quality of the services provided, compose our philosophy.

The services offered by THESIS, despite making the most of all available digital tools, always focus on the creativity of the people in order to ensure the required quality along with the accumulation of knowledge. Thus, in an economic environment that is changing dynamically and becoming more and more complex internationally, THESIS provides services that aim to enhance the sustainability of the business efforts of its customers.

THESIS supports and promotes the idea of ​​creating leaders who act either on the side of its customers or as its executives, adopting the principle that always in the new digital world that is rapidly rising and the focus should be the person. The creativity, the support of the talent and the understanding of all the documented views of the executives promotes the working environment of the Company, and is the practical proof of the adoption of proposals to the clients for the promotion of management models of financial and non-objects, with a characteristic element the value of knowledge and is the practical proof of the adoption of proposals to customers for the emergence of management models of financial and non-objects, with a characteristic element the value of knowledge created and evolved by thinking people. In this context, THESIS and its clientele form communities of beneficial development and not competitive relationships of ephemeral benefit.

THESIS is active in the social and economic changes in Greece, and participates in them by supporting initiatives that contribute to the strengthening of the Republic, the equality of citizens and the prosperity of social groups by adhering to the values ​​of Greek Culture. It is a Greek company that supplies creativity and talent, overcoming obstacles that distinguishes Greeks, adopts a strategy of coupling human capital, know- how and digital systems to support business efforts and entities at all stages of development and operation. It gives priority to the support of companies operating in Greece, in Europe, in the USA and in China and actively participates in the chambers that promote the business cooperation of Companies in Greece with Companies in these countries.

«Our People»

THESIS S.A is managed by a team of people who are inspired by the values of hat it practically adopts for its sustainable development. The leading team of THESIS is a sample of a composition of different characters and executives with different backgrounds who act harmoniously accepting common values ​​and development policy of the Company. The leadership team is developed and supplemented with the aim of promoting all the executives who belong to the THESIS family. (See the leadership team here)

The collective work and the model of administrative governance with a focus on the utilization of the experience and the ability of all the executives are the elements that highlight the quality of the services offered by THESIS and the value and reputation that it has acquired.

All its executives develop their skills through an endless spiral process of developing their know-how in financial and consulting services. At the same time, they develop the ability of human communication with the aim of consolidating a functional and useful channel for the exchange of information and the understanding of business action experiences with customers.

«How we operate»

The success of our company is a result of how we treat our clients and their business. Our work is supported by proactive advice and specialist knowledge, and always has a personalized flavor for assisting clients to attain business goals.

The main structure of the team assigned to each customer is described in the below chart:

Depending on the needs of each customer, the above structure maybe altered in order to meet the individual challenges they face and to make sure that they will receive the highest level of expertise.

Our company has a rigorous training program in place to ensure that all of our staff are well vetted with recent tax changes and accounting rulings, and for enhancing expertise especially working within new digital business ecosystems.

THESIS maintains the highest standards of confidentiality and business quality certified by ISO/IEC 27001:2013 (Information Security Management System), and EN ISO 9001:2015 (Quality Management System).

THESIS clientele is consisted of:

70% Multinational Organizations
15% Greek owned entities
10% Public Sector entities
5% Non-Profit Organizations

THESIS office premises are based close to Metro station of Megaron-Athens Concert Center. Nonetheless, many of the services are provided in a timely and efficient way through a well-structured remote work model.

Leading team

The Partners and Managers of the Company are graduate Economists with extensive professional experience in Greek and International companies.

Yiannis Melemenis , President and Co-Founder of the company, Graduate of the Economic University (Athens) with Postgraduate studies in Taxation .

Takis Arkoulis , Managing Partner and Co-Founder of the company, Graduate of Athens University (School of Law Dept. of Economics). Postgraduate studies in Taxation and specialized in Auditing .

Thanasis Maniotis, Tax Partner, Graduate of the Economic University of Piraeus with high level expertise in Taxation, IFRS, and Tax Planning Strategies .

George Kouros. Public Sector Partner, Graduate of the Athens University of Economic & Business, with high level expertise in Management Accounting Procedures, and International Public Sector Accounting Standards.

Dimitris Melemenis. Consulting Partner, Graduate of the Middlesex University (London). Postgraduate studies in Business Information Systems, and establishment of best-practice ERP processes.

Dimitris Rigas. Internal Audit & Finance Partner, Graduate of the Athens University of Economic & Business, with postgraduate studies in IFRS, Risk Analysis & Management Accounting, Certified Internal Auditor.

Panayotis Vassilakis. Transfer Pricing Partner, Engineer with PhD in Management Decision Making with Artificial Intelligence methods, Professor in University of the Aegean Department of Financial and Management Engineering, high-level Innovation External Expert for European Commission (evaluation & review of grant applications, projects and tenders).


The Firm employs a total of twenty-three (23) professionals. Twenty (20) of them are University Degree holders and three (3) of them are employed as Administrators. Training and study courses are made available to the personnel in order to enhance their knowledge and assist them in their professional development.

The Personnel Turnover of THESIS SA compared to other Consulting Firms (including multinational) is the lowest in the market. It fluctuates between 3% – 5% annual.


In addition, our company has created the service @onTHESIS, an Open
Line Support Service in Tax and Accounting issues of current nature, offering
a complementary service of High Advisory Value to companies that have an
organized administrative Unit of Accounting and Financial Management.



THESIS SA supports, the activities of the below mentioned Non Governmental Organizations:

Athletic Association ILISIAKOS (Volley Ball team)

THESIS SA buys all business gifts from ROUSSOS ANTIQUES

This website uses cookies and asks your personal data to enhance your browsing experience.