- Graduate “Anatolia” College, Thessaloniki, 1962
- Graduate Aristotle University of Thessaloniki, Dpt. of Agricultural Sciences, 1967
- Honorary Doctorate, Kingston University, England
- Chairman REDESTOS - Efthymiadis Agrotechnology Group, established 1935. A leading business group in Greece and Southeast Europe in the field of Agricultural technology, supplies and services.
- President of the Thessaloniki Technology Park (1994 till today)
- President of the Federation of Industries of Northern Greece – FING (1994-1997)
- Chairman of the STABILITY PACT / Business Advisory Council for Southeast Europe, Brussels (2005-2006)
- Chairman of the Business Development Centre – KEPA (2015-2017)
- President of the Northern Greece Businessmen’s Cultural Association (2004-2010)
- Vice President of the Center for Democracy and Reconciliation in S.E. Europe – CDRSEE (2013-2018)
- Chairman of the Business Information and Clearing Center – BICC (2001-2015)
- President of the Industrial Dept. and Member by the Excellence of the Board of the Thessaloniki Chamber of Commerce and Industry (2006-2011)
- Chairman of the Permanent Committee for Trade Facilitation – Hellaspro (1998-2001)
Contributed to several European think tanks on development and cooperation in Southeast European region. Mr. Efthymiadis is also Honorary Consul of the Kingdom of the Netherlands in Thessaloniki.