One hundred and seventy-one unrelated elderly healthy subjects selected according to the Senieur protocol (57 men and 114 women), aged 75-104 years, and 405 healthy individuals (238 men and 167 women), aged 18-65 years, were typed for HLA-A, HLA-B, and HLA-DR antigens. The purpose of the study was to investigate a possible association between HLA antigens and longevity. In the total group of elderly, an increased frequency of HLA-B16 (11.11 vs. 5.43%) and HLA-DR7 (38.33 vs. 15.67%) and a decreased frequency of HLA-B15 (1.75 vs. 5.18%) and HLA-DR4 (11.66 vs. 24.15%) were observed. The HLA-B15DR4 haplotype was not represented (vs. 2.1%), HLA-A1B8 was found with a low frequency (2.9 vs. 4.4%), and HLA-B8DR3 was very rarely found (1.6 vs. 10.1%), whereas the HLA-B13DR7 haplotype was observed with an increased frequency (6.6 vs. 3.3%). These results are in agreement with other published data and suggest that longevity in humans may be influenced by the genetic background.