The authors evaluated methylmethacrylate as an adjunct to internal fixation of 47 pathologic fractures of long bones (10 of the humerus and 37 of the femur) in 43 patients with metastatic disease. In their experience this method proved to be vastly superior to other methods of internal fixation. All patients were relieved of pain and, if able to walk, could do so almost immediately after fixation of the fracture. In the others comfort was enhanced and nursing greatly facilitated. The surgical technique of internal fixation is described in detail. Correct selection of the metal implant, meticulous attention to the biomechanical considerations and restoration of bone continuity by means of methylmethacrylate are most important if a gratifying result is to be obtained.