Eighty patients received 179 courses of therapy for osseous metastasis from mammary cancer. Relief of pain which persisted for at least three months occurred in 37% of courses of therapy and a favorable objective therapeutic response (regression or nonprogression) in 23% of courses. Duration of objective response ranged from 3 to 17 months, with a median duration of five months. Both subjectively and objectively, radiation therapy was the most effective form of therapy for localized osseous metastases. Chemotherapy and adrenocortical steroids were more effective for diffuse osseous disease than other additive or ablative hormonal therapies.