Use of antibiotic prophylaxis (AP) in clean breast cancer surgery is still controversial. We assessed the efficacy of preoperative AP in a prospective study of 171 clean breast cancer procedures following previous anticancer chemotherapy. From June 1998 to July 2001, we analyzed 171 procedures. In 133 cases. AB with cefuroxime was performed. Wound infection rate was 3 out of 171 procedures (WI rate of 2/131 with AP compared with 1/37 without AP, p = 1.0). This study suggests that AP is not systematically required in breast cancer surgery following previous anticancer chemotherapy.