DNA oligotyping was used to determine HLA-A28 subtypes in 25 unrelated Caucasian individuals living in or around Seville, Spain. Results showed that HLA-A*6802 was the most frequent allele, found in 14 individuals (53.8%), followed by HLA-68.3, which was present in eight subjects (30.8%), and both combined represented 84.6% of A28+ individuals in the area. The HLA-A*6801 allele was found in three individuals (11.5%), whereas HLA-A*6901 was present in one subject only (3.8%). Results indicate that the distribution of HLA-A28 alleles can vary among different Caucasoid populations. In this way, the high frequency obtained for A*6802 supports previous studies suggesting that the HLA-A*6802 allele was prevalent in people of the Mediterranean basin, in contrast to A*6801, prevalent in northern European populations.