OBJECTIVE: A genetic predisposition is widely accepted in schizophrenia. This study was intended to find any association of HLA-DRB1 alleles with Korean schizophrenics and thereby compare the results of other ethnic groups. METHODS: The subjects were 70 unrelated Korean patients. Low and high resolution typing of HLA-DRB1 alleles were performed. The comparison groups were 2,000 unrelated healthy Koreans for low resolution HLA-DR and 229 unrelated healthy Koreans for HLA-DRB1 alleles. RESULTS: Gene frequencies of HLA-DR11(patients 9.0%, healthy control 3.8%, p=0.005) and HLA-DRB1*1101(patients 9.0%, healthy control 1.8%, p< .001) were significantly higher in Korean schizophrenics. CONCLUSIONS: The frequency of HLA-DR11 (HLA-DRB1*1101) is significantly higher in Korean schizophrenics than in healthy Koreans. HLA-DR4 and HLA-DR1, which were known to be associated with Caucasian and Japanese schizophrenics, respectively, did not show statistical association with Korean schizophrenics. This association need to be reassured through further studies with families or association study with larger numbers of subjects.