Data are presented on several polymorphic genetic markers in 200 Greek gypsies. Polymorphic loci studied were: the ABO, MN, Rhesus, Kell and Duffy blood groups, hemoglobin, and ceruloplasmin. A survey for congenital malformations and hereditary diseases was also carried out on this group. The ABO, Rhesus, MN and Duffy system frequencies varied significantly from the figures obtained for the Greek population. However, there is a characteristic similarity between various gypsy groups studied in other nations and the distribution of polymorphic traits in the Punjab region of India. Cystic fibrosis, renal tubular acidosis, 21‐hydroxylase deficiency, Holt‐Oram syndrome and homozygous (3‐tha‐lassemia were diagnosed within the gypsy group