© 2019 American Society for Bone and Mineral Research. Drug-induced osteoporosis is the most common secondary cause of bone loss leading to fractures, and glucocorticoids constitute the class of drug most typically associated with this form of osteoporosis. A mouse model of glucocorticoid-induced osteoporosis (GIOP) demonstrated that glucocorticoids reduce osteoblast and osteocyte differentiation and lifespan via increased apoptosis. Glucocorticoids have effects on muscle, leading to the classic loss of muscle mass noted in patients with endogenous or exogenous glucocorticoid excess. GIOP illustrates the importance of careful medical history taking and physical examination for the evaluation of osteoporosis. Magnetic resonance imaging of GIOP patients may hold some promise for fracture risk assessment. Sufficient calcium and vitamin D are necessary but generally insufficient by themselves for most long-term glucocorticoid users to maintain adequate bone health. A meta-analysis of bisphosphonate use in GIOP demonstrated fracture risk reductions that were similar in magnitude to those seen in postmenopausal osteoporosis.