Inhaled corticosteroids are the cornerstone of the modern therapy for asthma. In recent years, inhaled corticosteroids have been used in higher doses than previously. This has caused concern about possible osteoporotic side-effects. We studied bone mineral densities (BMDs) in 19 non-smoking women (mean age 53 years, range 40-63) with newly diagnosed bronchial asthma and 19 voluntary healthy non-smoking women (mean age 53 years, range 43-67). In both groups, 13 subjects were postmenopausal. Patients started beclomethasone dipropionate from the spacer 500 micrograms twice daily as the sole corticosteroid therapy. BMDs were measured with dual-energy x-ray absorptiometry (DEXA) at the lumbar spine (L2-4) and at the left proximal femur (the neck, Ward's triangle and the trochanteric region). The measurements were made at baseline and 6 and 12 months thereafter. No significant changes were observed in the measured BMDs in either study group. The results show that inhaled beclomethasone dipropionate therapy 1000 micrograms/day for one year does not affect BMD. Further studies are needed to assess the effects of inhaled corticosteroid on BMD during a longer treatment period.