Gynecomastia is a benign enlargement of the male breast secondary to gland proliferation. Subcutaneous mastectomy is performed for symptomatic patients and in those desiring cosmetic changes. The aim of this study was to assess the risk factors and complications associated with the operation. We retrospectively examined the records of all patients undergoing a subcutaneous mastectomy for gynecomastia. Ninety-one patients were identified. We conducted telephone interviews with 52 patients and performed 65 subcutaneous mastectomies on those 52 patients. Thirty of the 65 procedures (46%) developed complications. These included sensory changes, pain, seromas, scarring, breast asymmetry, hematomas, and wound infection. No preoperative risk factors were significant for postoperative complications. Eighteen of 22 cases with drains placed intraoperatively developed complications as compared with 12 of 43 cases without drains (P = 2.6 x 10(-7)). Specimens removed from the patients who had drains placed were significantly larger than those from patients who did not have drains placed (P = 1.5 x 10(-5)). However, specimen size was not an independent risk factor for development of a complication (P = 0.14). We found a relatively high complication rate in subcutaneous mastectomy for gynecomastia. Most complications are minor with no long-term effect. Drain placement was the only risk factor associated with postoperative complications.