The prevalence of hepatitis B virus (HBV), hepatitis delta virus (HDV), and human immunodeficiency virus (HIV) infections were determined in 102 patients on regular hemodialysis, 82 kidney recipients and 103 nondialyzed, nontransplanted patients with various renal diseases. The prevalence rates of hepatitis B surface antigen (HBsAg) in dialysis and renal transplant patients (12.7% and 11.0% respectively) were significantly higher than the rate in a control group of patients who had never been dialyzed nor transplanted (2.9%, P0.05). In patients who were HBsAg positive, evidence of HDV infection was found in one dialysis and two transplant patients only. HIV infection was confirmed in only two of 102 (2.0%) and three of 82 (3.7%) hemodialysis and kidney recipients respectively. These data indicate that hepatitis B, delta and HIV infections are major health problems among hemodialysis and renal transplant patients in the Sultanate of Oman.