The results of blood, serum, and enzyme group typings on a sample of 295 unrelated Irish males aged from 20–30 are reported. The gene frequencies concerning the polymorphisms MNS, Rh, Kell, Hp, Gc, Gm, Inv, red cell acid phosphatases and adenylate kinase do not differ obviously from those of other European populations. On the other hand our Irish sample differs regarding the gene frequencies of the ABO, P, Duffy, and PGMr polymorphisms, and in the frequencies of the alkaline serum phosphatase phenotypes. Finally, the gene distribution of the Irish seems to be more similar to those of the Icelanders as compared to other Europeans.