112 Greeks living in W. Germany and coming from various parts of Greece and 280 individuals from the Isle of Alonissos (northern Aegean Sea) have been typed for seven polymorphic red cell enzymes, namely red cell acid phosphatase (aP), phosphoglucomutase (PGM1) adenylate kinase (AK), 6-phosphogluconate dehydrogenase (6-PGD), esterase D (EsD), glutamic-pyruvic transaminase (GPT), and glyoxylase I (GLO). The gene frequencies obtained in these two samples are compared with the hitherto reported corresponding data from other Greek populations. Finally genetic distances (basing on six polymorphic serum protein and red cell enzyme systems) have been computed for seven Greek population samples. The results of these distance measurements are discussed.