Prevalence of hepatitis B and C virus infection amongst intravenous drug users (IDU) in Nepal is not known. To estimate such prevalence 72 IDU individuals were tested for HBV and HCV markers. About 80% of the drug abusers are both anti-HBc (59/72) and anti-HCV (58/72) sero-positive. However persistent infection with hepatitis B, as indicated by positive HBsAg, was detected in only 5.5% (n = 4). Active hepatitis C infection, as indicated by HCV RNA positivity, was documented in 74% (42/58) of those who were anti-HCV positive. Importance of awareness of this observation among the healthcare workers in the prevention of hepatitis C in the community is stressed.