Hepatitis C virus infection has been associated with a variety of extrahepatic disorders. We report four patients with membranous glomerulonephritis and hepatitis C virus infection. In contrast to patients previously reported with HCV infection and membranoproliferative glomerulonephritis, these patients have normal or minimally reduced complement levels and no evidence of rheumatoid factor or cryoglobulinemia. A liver biopsy in one patient was consistent with chronic active hepatitis although liver enzymes were only minimally elevated and coagulation studies normal. Three patients were treated with alpha-interferon with some success. Treatment with alpha-interferon may have a beneficial effect in reducing proteinuria and improving liver function and may be related to the ability of interferon to suppress viremia. Future studies need to focus on clarifying the role of the virus in causing glomerular disease and improving dosing strategies for alpha-interferon. Randomized, controlled studies need to be performed to determine whether the beneficial effect of alpha interferon is significant, and if so, if it is superior to conventional therapies.