Androgen deprivation therapy (ADT) alone or in combination with radiation therapy or other drugs is increasingly used for the treatment of localized, high-risk, or biochemical relapse of prostate cancer (PC). Bone mineral density (BMD) loss is rapid during the first year of ADT; up to 4.6% of total hip, femoral neck, and lumbar spine BMD loss has been reported in PC patients without bone metastases (nonmetastatic PC). In prospective studies, concurrent administration of a bisphosphonate or selective estrogen receptor modulator stabilized or increased BMD. Results of retrospective studies of ADT-treated patients who did not receive antiresorptive therapy have demonstrated a 21-37% increase in fracture risk. Because of the documented bone loss and increased fracture risk, patients should receive adequate counseling, monitoring, and therapy aimed at preventing or treating ADT-induced bone loss. Future studies should address the long-term impact of antiresorptive therapy on actual fracture rate and the impact on quality of life and healthcare costs.