We report a 50-year-old male patient with hepatitis C virus (HCV)-associated membranous glomer ulonephritis (MN), for which he had been treated with corticosteroid therapy for one and a half years. This patient received blood infusion at 38 years of age. He visited our hospital because of liver dysfunction at 42 years. One year later, proteinuria and microhematuria were pointed out (43 years). Renal biopsy revealed MN with focal fibrocellular crescents. HBsAg, cryoglobulin, rheumatoid factor were all negative. Prednisolone was administered at the dose of 30 mg/day for 4 weeks and tapered subsequently. The steroid treatment was effective (urinary protein excretion: 4.2→0.3 g/day, serum albumin: 2.4→4.0 g/dl, 3 months later), and transaminase slightly elevated (GPT 50→60-80 IU/l). One and a half years later he proved to be positive for HCV antibody, and corticosteroid administration was terminated. Subsequently proteinuria increased, and reached 3.0 g/day 6 years later. However, serological markers and ultrasonographic study for chronic hepatitis revealed mild changes of the liver. These findings suggest that corticosteroid therapy is not contraindicated against HCV-associated MN, and may possibly be used as the treatment for this condition.