General complications, wound complications and hospital stay after surgery for operable mammary carcinoma were studied prospectively in 385 patients treated by either modified radical mastectomy (324 operations) or segmental resection with axillary dissection (71 operations). The overall infection rate was 3.6 per cent. Postoperative seromas were noted in 34.8 per cent of the wounds. Other complications were few. The average hospital stay was 7.2 days. Seventeen per cent of the total number of days in hospital for these patients were due to factors other than the mammary cancer.