Background Since primary biliary cirrhosis (PBC) is usually diagnosed in postmenopausal women with minor cholestasis, it has been questioned whether PBC itself represents a further risk for osteoporosis. Aim To assess the prevalence and risk factors for osteoporosis in an unselected series of women with PBC. Patients and Methods 142 women with PBC (age: 54.3±0.8 years) and an age-matched control group. Osteoporosis was established by densitometry (bone mineral density below −2.5 T-score). Age, duration and severity of PBC, body mass index, menopausal status, histological stage and markers of bone turnover were assessed. Results Prevalence of osteoporosis was higher in PBC (32.4%) than in normal women (11. 1%) (RR: 3.83, 95%CI: 2.59–5.67, P<0.001). Osteoporosis was associated with older age, menopausal status, body mass index, longer PBC duration, advanced histological stage, high bilirubin and alkaline phosphatase, and low albumin and prothrombin index. Regression analysis identified older age, higher Mayo risk score, lower body mass index and advanced histological stage but not menopause as the independent risk factors for osteoporosis. Conclusions Osteoporosis is more prevalent in women with PBC than in the general population. Age and severity of the disease, but not menopausal status, are the main risk factors for osteoporosis in this liver disease.