The distribution of HLA-D region antigens was studied in 17 patients with well-documented polymyalgia rheumatica (PMR). HLA-D region antigens were defined by the oligonucleotide typing of polymerase chain reaction (PCR)-amplified genomic DNA. The results demonstrate that the prevalence of DR4 was significantly higher (p < 0.0002; RR = 8.10) in patients (70.6%) compared to normal controls (22.9%), and the frequency of DR1 and/or DR4 in patients (82.4%) was also higher (p < 0.0006; RR = 8.40) than that in normal healthy controls (35.7%). Of the subtypes of DR4,Dw13 was significantly higher (p < 0.002; RR = 9.30) in patients (29.4%) than in normal controls (4.3%). However, these data must still be confirmed by other investigators. The distribution of the remaining DR antigens and of the DQ and DP alleles in patients did not differ significantly from those in controls. The results suggest immunogenetic similarity between PMR and late onset rheumatoid arthritis in elderly populations.