Panagiotis Markopoulos worked as a Certified Public Accountant of the Body of Certified Public Accountants (SOL) from 1975 to 1993. From 1993 to 2012, he worked as a Certified Public Accountant for Crowe Greece (former SOL S.A.) and was one of its founding members. From 1981 to 1987 and from 1989 to 1996 he was elected as a member of the Board of Directors for the Association of the members of the Institute of CPA (Member, General Secretary, Vice President and President). From 1988 to 2005, he was a Member of the Board of Directors of the Public Enterprise of Negotiable Securities. From 1996 to 2006, he worked as a Certified Public Accountant – Member of the Supervisory Council of the Institute of Certified Public Accountants of Greece (SOEL). From 1992 to 2007, he was a member of the Assembly of Delegates of the Economic Chamber of Greece. From 1996 to 2012, he worked as a Certified Public Accountant, Chairman of the Board of Directors and Managing Director of Crowe Greece (former SOL SA.). From 2013 to 2020, he was Chairman of the Board of Directors of Crowe Greece Consulting and Special Advisor to Crowe Greece. Since 2020, he has been the Vice Chairman of Crowe Greece Consulting.

He has participated in several training seminars of the Institute of Certified Public Accountants and, in particular, concerning Accounting, Auditing, the Charts of Accounts and their Standards, for all the sectors of the Greek economy (Commercial and Industrial companies, Banking Institutions, Insurance Funds, Public Entities, Technical & Shipping companies, Valuations - Conversions - Mergers, Bankruptcies, Expert reports, Applied Information Technology etc.).