Glucocorticoid treatment can alter bone metabolism, reduce bone strength, and increase the risk for osteoporotic fractures. Risk factors for glucocorticoid-induced osteoporosis (GIO) include older age, high doses, and longer duration of glucocorticoid use. The bone loss that accompanies glucocorticoid use is rapid, and early treatment with bone-sparing agents can prevent bone loss and reduce fracture risk. Several randomized controlled clinical trials have found prevention and treatment of GIO with bisphosphonates, and recently the treatment of GIO with teriparatide, to be effective. This article reviews current information on the epidemiology, pathophysiology, and clinical studies that support using bone-active agents to prevent and treat GIO.