Graves' disease has been associated with different human leukocyte antigen (HLA) genes in different races. To evaluate the association of HLA type in Taiwanese with Graves' disease, the HLA-A, -B, and -DRB1 alleles in a total of 236 Taiwanese adults with Graves' disease and 533 racially matched normal control subjects were examined using the PCR-SSOP (sequence specific oligonucleotide probe) technique. The prevalence of HLA-A*0207, -B*2704, -B*4601, and -DRB1*0901 among patients with Graves' disease was found to be increased, with odds ratios (OR) of 2.21, 3.82, 1.76 and 1.62, respectively. However, after correction for multiple comparisons, the relative risk of HLA-A*0207 susceptibility to Graves' disease remained statistically significant and the haplotype HLA-A*3303 -B*5801 -DRB1*0301 had a significantly protective effect. None of the other 2- or 3-locus haplotypes showed any significantly increased risk. Although HLA-DRB1*1405 showed an increased relative risk in patients with GO (Graves' opthalmopathy) (OR 4.61) when compared with patients without GO, the relative risk after adjusting for the number of comparisons was not significant. Taiwanese patients with Graves' disease have HLA-associated susceptibility genes which are similar to those found in Chinese patients in Hong Kong and Singapore. However, the finding in this study of a higher frequency of HLA-A*0207 in Taiwanese with Graves' disease has not been documented in any other ethnic group.