Primary sclerosing cholangitis (PSC) is a disease of the bile ducts which frequently is associated with inflammatory bowel disease. The disease is characterized by stenoses and saccular dilatations of the intra- and/or extra-hepatic bile ducts. Endoscopic retrograde cholangiography is the mainstay of diagnosis of this disease. A liver biopsy gives additional information and is particularly useful to rule out secondary cirrhosis. In a series of 50 patients the 5-year survival was 85%. The etiology is unknown, but in addition to inflammatory bowel disease the disease is associated with the autoimmune haplotype HLA-A1, B8, and DR3. Antibodies to perinuclear antigens in leukocytes are present in 65% of patients with PSC. Ursodeoxycholic acid therapy causes an improvement of symptoms and a decrease of elevated liver enzyme values. There are no drugs as yet with a proven effect on fibrosis or cirrhosis in this disease. Liver transplantation in this disease has a reported 4-year survival of 88%.