HLA-ABC and DR antigens were studied in 704 unrelated Danes (84 cadaver kidney donors, 307 healthy individuals, and 313 uremic patients), HLA-DR1, 2, 3, 4, 7, w8, and w10 were investigated in all individuals, whereas DR5, "DRw6", and w9 were only studied in parts of the material. The frequencies of DR1, 2, 3, 4, 5, and w10 were similar in the three groups, while those of "DRw6", DR7 and w8 differed significantly. The deviation of the DR7 frequency was small and probably due to change; "DRw6" is considered difficult to define, and DRw8 may have been difficult to define in the early part of the material. DR-phenotype distributions showed perfect fits to Hardy-Weinberg expectations for the three groups separately and for the combined group. When our combined DR antigen frequencies were compared with those from another Danish sample (Madsen et al, 1981), significant differences were found for "DRw6", w8 and w10. However, in general, the same HLA-B,DR phenotype combinations showed significant positive associations in the two samples, and most of the corresponding haplotype frequencies and delta values were quite similar.