We examined the presenting features, clinical course and prognosis in relation to age in 121 patients with primary biliary cirrhosis (PBC) for a mean follow-up of 4.6 years. 35 patients (29%) were over age 65 years at presentation/detection. There was a higher proportion of patients asymptomatic of liver disease in the older (over 65 years old) than younger (under 65 years old) group. The clinical features of PBC were less marked in the older patients both in number of symptoms (p < 0.05) and in progression of serum bilirubin, a marker of prognosis (p < 0.001). There was no difference in liver-related mortality between old and young patients during the follow-up period. Overall mortality in patients with PBC presenting over age 65 was no different from age- and sex-matched controls.