BACKGROUND: Osteoporosis has been reported in patients with chronic obstructive pulmonary disease, but this association is not well established. This study was undertaken to determine whether the prevalence of osteoporosis was increased in patients with chronic obstructive pulmonary disease and we examined the relationship of corticosteroid administration with osteoporosis. METHOD: Subjects were 23 patients with chronic obstructive pulmonary disease and 20 control patients. We reviewed hospital records and measured bone mineral density using dual-energy x-ray absorptiometry(Lunar, USA). RESULTS: Mean bone mineral density(BMD) of spine in COPD group was 0.683+/-.154 g/cm2 and 0.971 +/-.212g/cm2 in controls(p<0.01). But there was no significant difference in femoral neck BMD. There were seventeen cases of osteoporosis and six cases of osteopenia in COPD group and three patients of osteoporosis and one case of osteopenia in controls. But, there was no significant correlation between disease duration of COPD and spinal T score(r=-0.395, p>0.05). Ten patients were received corticosteroid in COPD group. Spinal T score in steroid receiving patients were -3.82+/-.94(SD) and -2.82+/-.97(SD) in not having steroid patients(p<0.01). Cumulative dose of corticosteroid was associated with spinal T score(r=-0.424, p<0.05) and duration of corticosteroid administration also associated with spinal T-score(r=-0.457, p<0.05). Spinal BMD of patients not having corticosteroid in COPD group(n=13) were significantly lower than that of controls(0.71+/-.13 g/cm2 and 0.97+/-.21 g/cm2, p<0.01). CONCLUSION: Prevalence of osteoporosis is increased in patients with chronic obstructive pulmonary disease. Especially patients who are receiving corticosteroid have high risk of osteoporosis or osteopenia and need for preventive management.