Supraphysiologic levels of glucocorticoids result in substantial bone loss, particularly at sites rich in trabecular bone. This results in fractures, typically in the vertebrae and ribs, in up to one third of long-term steroid users. Patients requiring long-term steroid treatment or with incurable Cushing's syndrome should have a bone density measurement, preferably at the spine. They should be offered specific prophylaxis against bone loss if their bone density is in the lower part of the young normal range, or below. Treatment should consist of sex hormone replacement in hypogonadal subjects, a bisphosphonate, or possibly a vitamin D metabolite. These medications can be used in combination. Correction of vitamin D deficiency, provision of calcium supplementation, cessation of smoking, and the provision of adequate exercise are sensible adjunctive interventions. Attention to the issue of steroid osteoporosis before fractures occur will substantially reduce the skeletal morbidity attendant upon the use of these lifesaving medications.