Saliva and urine samples from six GB virus C (GBV-C)/hepatitis G virus (HGV)-infected renal transplant patients were tested by RT-PCR. Viral RNA was detected in all saliva samples, but the viral RNA titers in saliva were 100 to 10,000 lower than those in the corresponding sera. Comparative sequence analysis of the amplified 354 bp DNA from one patient revealed full identity of GBV-C/HGV variants present in serum and saliva. None of the urine samples from the six patients was found to contain GBV-C/HGV RNA. High prevalence of GBV-C/HGV RNA in saliva of infected individuals may contribute to a wide spread of GBV-C/HGV infection, at least in some settings.