To assess the impact of primary biliary cirrhosis on bone mass in general and the relative importance of the stage of the liver disease and of treatment with glucocorticoids for the possible development of osteoporosis, bone mineral mass was measured by single and dual photon absorptiometry in 55 unselected female patients with longstanding primary biliary cirrhosis. Although most of the patients had a bone mineral density within the normal range, the bone mineral densities of the lumbar spine and distal and proximal forearm were 8% (P less than 0.004), 8% (P less than 0.03), and 5% (NS) respectively, lower than in age-matched healthy women. Multiple regression analysis showed that the histological stage of the liver disease (early stage vs. late stage) was an independent determinant of axial bone mineral density, whereas the use of glucocorticoids resulted in only a moderate and not significant bone loss. Serum calcium proved to be significantly lower in the patients with late-stage primary biliary cirrhosis than in those with early-stage disease, whereas no significant differences were found in these groups with regard to several biochemical parameters of bone metabolism. In conclusion, in patients with primary biliary cirrhosis, bone loss was only moderate and related to the histological stage. The effect of low-dose glucocorticoids on bone mass seemed not significant.