Osteopenia and osteoporosis are increasingly common in cancer patients, owing to the aging of the population and to new forms of cancer treatment. Androgen and estrogen deprivation, as well as some forms of cytotoxic chemotherapy, may lead to osteopenia and osteoporosis. Patients at risk for osteoporosis include those treated with aromatase inhibitors and with androgen deprivation for more than 1 year. In addition, all patients 65 years of age and older are at risk of osteoporosis when treated with cytotoxic agents, and so should be screened for bone loss. Several treatments have been effective in the prevention and management of osteoporosis. In patients at risk for this complication, it is recommended to obtain a bone density evaluation and to start appropriate treatment. This may include calcium and vitamin D supplementation for mild forms of osteopenia, and bisphosphonate therapy or denosumab (Prolia) for more advanced osteopenia and osteoporosis.