Primary biliary cirrhosis is infrequently diagnosed in men, so that the clinical, biochemical and histopathological spectrum of this disease in men has not been evaluated. Therefore, we studied 30 men who had a histological diagnosis of primary biliary cirrhosis and had positive tests for antimitochondrial antibodies. Five patients had no hepatobiliary symptoms, and two of these patients had neither biochemical nor histological evidence of cholestasis. These 30 male patients' findings were compared with the findings in 30 age-matched women who also had primary biliary cirrhosis and antimitochondrial antibodies. Six of these patients were asymptomatic. Clinical findings and symptomatic status, in addition to biochemical and histopathological features, were generally similar in both male and female patients. The possible significance of higher serum alkaline phosphatase activities and lower frequency of occurrence of piecemeal necrosis in men with primary biliary cirrhosis, as compared with women, requires further study.