Summary. Glucocorticoids are the most frequent cause of secondary osteoporosis. They are responsible for both inadequate quantitative and qualitative effects on bone, primarily on osteoblasts (decreased activity and apoptosis). Studies have shown that patients taking glucocorticoids have decreased bone mineral density and increased risk for fractures, especially for post- menopausal women. Prevention of glucocorticoid-induced osteoporosis includes use of the lowest effective glucocorticoid dose possible, calcium and vitamin D supplementation, hormone replacement therapy and adequate physical activity. Prevention of fractures also includes all those factors that can influence the balance (e.g. muscle strenghtening, walking aids, architectonic barriers). Antiresorptive drugs should be started in all the patients with increased risk for osteoporosis, and among them bispho- sphonates are the first drugs of choice.