Review of patients with pathologic fracture of the humerus disclosed that closed treatment resulted in a high incidence of pain, disability, and failure to heal. The most common cause of pathologic fracture of the humerus is breast cancer. A review of records of 103 patients with persistent disease after initial treatment for breast cancer revealed that 19 had humeral metastases (18.5%); of those with humeral metastases, two patients (10%) had pathologic fractures. Prophylactic internal fixation of humeral metastases is not routinely recommended, but operative treatment for pathologic fracture of the humerus is generally superior to nonoperative methods of fracture management.