Background. Hemodialysis (HD) patients are at high risk for hepatitis B virus (HBV) infection due to intravenous interventions and therapies: Our aim was to examine how genetic factors affect the response to HBV vaccination in HD patients. Methods. The frequencies of HLA class I and II alleles were investigated in responders and nonresponders. Response to vaccination was defined as anti-HBsAg > 10 SI U/L (group I). Nonresponders (anti-HBsAg < 10 SI U/L) were defined as group II. The study included HD patients who were negative for antibodies to hepatitis B surface antigen during pretransplantation evaluation. Results. Group I consisting of 166 patients and group II, of 90 patients showed a significantly higher frequency of the HLA A3 allele in group I (n = 20) than group II (n = 3) (P = .02). There were no statistical differences between the two groups regarding age and gender distribution (P > .05). Graft outcome was not different between responders and nonresponders (P > .05). Conclusions. This preliminary study shows that HLA alleles may have immunomodulatory effects in end-stage renal failure patients. The response to hepatitis B vaccination is affected in multifactorially fashion; HLA A3 may be a genetic predictor for responders, but further studies in larger series are required.