A 33-year-old woman was admitted to our department for evaluation of liver dysfunction and proteinuria. A liver biopsy specimen showed ductular proliferation and moderate portal fibrosis indicating stage II primary biliary cirrhosis. A renal biopsy specimen showed mild to moderate mesangial cell proliferation without crescent formation or interstitial nephritis. Immunofluorescent staining revealed deposition of immunoglobulin G (IgG), third component of complement (C3), and Clq on glomerular basement membranes. The findings indicated stage I membranous glomerulonephritis. Administration of ursodesoxycholic acid together with prednisolone, azathioprine, and dipyridamole decreased proteinuria and improved cholestatic liver dysfunction.(Internal Medicine 38: 22-26, 1999)