The bone metabolism in patients with systemic lupus erythematosus (SLE) has previously been examined, but the results are conflicting. In the present study the bone mineral density (BMD) of the axial and the appendicular skeleton was examined by means of dual energy x-ray absorptiometry. The bone turnover was evaluated by means of biochemical markers in serum and urine in a prospective cohort consisting of 36 female and male SLE patients. Repeated measurements of BMD were performed for up to two years. The BMD was decreased in the hand and in the femoral neck but normal in the spine and in the distal forearm. A weak correlation was found between the BMD of the femoral neck and the total consumption of glucocorticoids. Apart from this finding the BMD was uninfluenced by treatment with glucocorticoids and cyclophosphamide. No significant changes of BMD were found during the follow-up period. The serum concentration of the carboxyterminal cross-linked telopeptide of type I collagen was increased in almost all patients, but no other biochemical markers of bone metabolism were abnormal.