Pituitary hormones have direct and indirect effects on bone remodeling, and skeletal fragility is a frequent complication of pituitary diseases. Fragility fractures may occur in many patients with prolactinomas, acromegaly, Cushing disease, and hypopituitarism. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density, making difficult the prediction of fractures in these settings. Treatment of excess and defective pituitary hormone generally improves skeletal health, although some patients remain at high risk for fractures, necessitating treatment with bone-active drugs.