Summary Glucocorticoids (GCs) are widely used for the treatment of various diseases, particularly in dermatology. However, there have been few reports about the outcome of treatment for GC-induced osteoporosis in patients with dermatological conditions receiving oral GCs. The present study was undertaken to prospectively evaluate the usefulness of etidronate for preventing steroid-induced osteoporosis in patients on prolonged GC therapy as routine clinical management. In total, 110 patients receiving oral GC therapy were enrolled into the study. Of these, 87 patients were evaluated (44 patients with collagen diseases, 13 patients with autoimmune bullous dermatoses, 19 patients with chronic eczema/dermatitis, 2 patients with toxicoderma/drug eruption and 9 others). Urinary deoxypyridinoline (DPD) was evaluated as a marker of bone resorption, and serum bone-specific alkaline phosphatase (BAP) as a marker of bone formation. Significant increases in urinary DPD were seen in the control group after oral GC therapy had been continued for ≥ 1 year. Treatment with etidronate suppressed this increase. When the patients were stratified according to gender, this improvement was more obvious in women. No significant difference in serum BAP level was found between the two groups. These results suggest that bisphosphonates may be useful for preventing steroid-induced osteoporosis in dermatology patients (particularly women) receiving oral GC therapy.