The surgical morbidity associated with aggressive preoperative chemotherapy in 106 patients with advanced primary breast cancer who had chemotherapy followed by mastectomy was examined. These patients were compared with a group of 91 consecutive patients who had mastectomy without preoperative chemotherapy. Strict operative criteria were used to determine the timing of mastectomy following chemotherapy. Wound infection rates were no different in the preoperative chemotherapy group compared to the mastectomy-alone groups (7% versus 4%; p = 0.62). The incidence of wound necrosis was similar (11% versus 6%; p = 0.29). Seroma formation was decreased significantly in the preoperative chemotherapy group compared to the mastectomy-alone group (15% versus 28%; p = 0.04). Intensive preoperative chemotherapy did not delay the reinstitution of postoperative treatment (30% versus 20%; p = 0.27). However, when delay in instituting postoperative chemotherapy was more than 30 days, there was a significant decrease in overall survival rate (p = 0.04). This study provides evidence that intensive preoperative chemotherapy and mastectomy can be performed without increased morbidity. Furthermore it is important to institute systemic chemotherapy within 30 days of mastectomy to achieve maximum survival.