The clinical features at the time of presentation and the outcome in 126 patients with primary sclerosing cholangitis were studied to clarify the natural history and prognosis in symptomatic and asymptomatic individuals. The median age of the patients at the time of presentation was 36 years, 62% were male, and 16% were asymptomatic. The median follow-up from time of presentation was 5.8 years. There were more patients who had liver transplants (21%) than patients who died of liver-related disease (16%); the estimated median survival to these end points was 12 years. Cholangiocarcinoma was found in 8 patients and in 23% of those undergoing liver transplantation. Asymptomatic patients had milder disease than symptomatic patients, but in a univariate analysis the presence of symptoms was not prognostically significant. On multivariate analysis, the following independent prognostic factors were found: hepatomegaly, splenomegaly, serum alkaline phosphatase, histological stage, and age. These features were combined to produce a prognostic model that should be valuable in the stratification of patients in clinical trials and in the timing of liver transplantation, particularly in those patients seen soon after presentation.