The back pain is increasingly becoming a major problem in the elderly people. The cause of back pain in the elderly patient is quite different from in the young subject. And relationship of the occurrence of osteoporosis with the incidence of fractures in general is currently regarded as a major factor. The authors performed clinical observation on 194 elderly patients who were treated for back pain during 5 years period from April, 1983 to April, 1988 at the Department of Orthopaedic Surgery, Severance Hospital and relationship between osteoporosis and compression fracture of spine was reviewed. The results were as follows : l. Among the 194 cases of back pain(28.3% of total admission cases), whose age were over 50: 142 cases were female and 52 cases were male, being more common in female. 2. Most common cause of back pain was the compression fracture of spine : 86 cases(44.3 %). Osteoporosis was associated with 66 cases(76.7%) out of 86 cases. 3. The number of compression fracture in same patient was more frequent in osteoporotic patient and thoracolumber junction (T12, Ll) was the major site of fracture (45.6%). Compression fracture of spine caused by osteoporosis occured at multiple level in 60.6%. 4. Twenty three cases(34.8%) of compression fracture of spine with osteoporosis were found to have previous history of fractures of spine and/or extremities by radiological examination. Regarding this results, compression fractures of spine was not infrequent cause of back pain in the elderly. It was thought that re-fracture of spine should be prevented by vigorous approach against osteoporosis along with the treatment of presenting fracture in these patients.