HLA--A and B antigen frequencies from 65 different population samples (61 European and 4 non-European) have been tabulated. Pairwise genetic distances were calculated between some of the populations using HLA--A and B data. The distances obtained with these two series were very strongly correlated. Distances obtained with ABO blood groups (in part of the material) showed weaker but still highly significant correlation with those obtained from combined HLA--A and B data. In general, neighbouring countries had low distances, and of the populations studied, Essen would represent the 'middle' population in Europe. The supposedly inbred population of Sardinia showed the highest distances. The data may be useful for comparison in new HLA studies and can be used for further phylogenic studies.