The special features of fractures, usually in the femur or the tibia, and their treatment in Paget's disease of bone are discussed. Osteotomy of the femur or tibia for marked deformity, and joint replacement of the hip or knee for painful arthritis can be carried out quite successfully. The high incidence of sarcomas arising in the humerus, the development of multiple sites of malignant change, and some features of tumors on the skull are noted.