The purpose of the present paper is to investigate the efficiency of the health system in Greece after the end of the World War II and the analysis of the results that may occur and their possible reconsideration. We are going to compare both weaknesses and achievements to relevant E.U s standards before and after the enlargement of the 25. The fore coming results are expected to be the investigation of the determinants of the health system evolution in Greece. The approach of the subject is going to be held through the review of relevant literature and moreover through the analysis of raw material, as they conclude from WHO, OECD and member-states data.