Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease with onset about menopause. To investigate its clinical features and the natural history in relation to age, we examined 86 consecutive patients with PBC (81 F, 5 M); 70 were less than 65 years (mean age 48 years) and 16 greater than 65 years (mean age 69 years). All patients were followed-up for 6 months-16 years (mean 4 years). Histological stage at presentation was comparable in the two groups, but among aged PBC subjects there was a significantly higher prevalence of asymptomatic patients (56% vs 24%, p less than 0.001). No significant differences were observed in the biochemical indices and immunological abnormalities. Survival curves showed no significant differences in PBC according to the age. Mortality was observed only in the group less than 65 years (15/70, 21.4%). In conclusion, the large proportion of asymptomatic subjects in the elderly PBC patients accounts for the similar survival in the two groups of patients.