A total of 455 patients were recruited to study the prevalence of hepatitis GB virus-C/hepatitis G virus viremia in Hong Kong. There was no significant increase in the prevalence of hepatitis GB virus-C viremia in asymptomatic hepatitis B virus- and hepatitis C virus-infected patients compared to that of controls (1.56% and 7.14%, respectively, vs 3.85%, both P = NS). Renal patients as a whole had a significantly higher prevalence of hepatitis GB virus-C viremia compared to that of controls (13.95% vs 3.85%, P = 0.0271). The duration of the replacement therapy, especially for patients with peritoneal dialysis was associated with a higher chance of hepatitis GB virus-C viremia. Among renal patients, renal transplanted patients had the highest prevalence of hepatitis GB virus-C viraemia (19.1%) probably because of a higher susceptibility as a result of immunosuppression. However, hepatitis GB virus-C viraemia did not cause liver biochemistry derangement in renal transplanted patients.