In recent years, hepatitis C virus infection has been reported to be typically associated with membranoproliferative glomerulonephritis and less frequently with membranous nephropathy. Treatment of hepatitis C with interferon-alpha can reduce viremia and improve renal disease. After liver transplantation for hepatitis C virus-associated liver failure, standard immunosuppressive protocols result in a significant increase in hepatitis C viremia. In this report we describe a patient with end-stage liver disease and biopsy-proven hepatitis C-associated glomerulonephritis who underwent liver transplantation. Within 1 month after transplantation, he developed a severe nephrotic syndrome that paralleled a marked increase in viremia. We discuss the possible pathogenic relationship between hepatitis C virus infection and the nephrotic syndrome that followed liver transplantation.