The increasing use of liver transplantation and new treatment regimens requires an accurate estimate of the prognosis in primary sclerosing cholangitis. To clarify the natural history and prognosis of this disease, we studied the clinical features at the time of presentation and the outcome in 77 consecutive patients admitted to our hospital. The median age at diagnosis of primary sclerosing cholangitis was 32.5 years; 66% of the patients were male; 76 had concomitant inflammatory bowel disease and two had celiac disease. Thirty-four patients were classified as asymptomatic at diagnosis of primary sclerosing cholangitis. The mean follow-up time was 6.2 years; 25 patients have died or been transplanted. Cholangiocarcinoma has been diagnosed in 11 patients (14%). Female patients have a significantly poorer survival rate than male patients. The bilirubin level was found to be an independent risk factor for both mortality/transplantation, and for the occurrence of cholangiocarcinoma. Age at diagnosis of primary sclerosing cholangitis was an additional risk factor of death/transplantation. As bilirubin is an important prognostic factor for the development of both cholangiocarcinoma and death/transplantation, the construction of prognostic indices seems to be of limited value in the timing of transplantation of the individual patient.