['Infection rates for breast surgery are 3 to 15 percent, higher than average for a clean surgical procedure. Preoperative and postoperative antibiotics have lowered infection rates in other surgical groups, yet there is no consensus on postoperative prophylactic antibiotic use in microsurgical breast reconstruction.', 'A retrospective review of consecutive patients who underwent autologous breast reconstruction between 2006 and 2009 was performed. Specific risk factors for autologous reconstruction were reviewed, including medical comorbidities, irradiation, and chemotherapy history. Data were collected on type and duration of prophylactic antibiotics. A prospective cohort of patients who received only 24 hours of postoperative antibiotics was identified. The incidence of surgical-site infections was measured using Centers for Disease Control and Prevention criteria.', 'A total of 256 patients with 360 microvascular breast reconstructions who received both preoperative and postoperative prophylactic antibiotics were analyzed. The overall surgical-site infection rate was 17.2 percent (44 of 256 patients). Surgical-site infection was correlated with increased age, tobacco use, and prior radiation. Duration of postoperative antibiotic use did not differ in those patients who developed surgical-site infections (6.2 versus 7.7 days; p = 0.19). Eighty-two patients (32 percent) received only 24 hours of postoperative antibiotics, while 174 (68 percent) received more than 24 hours of antibiotics for a median duration of 10 days. There was no difference in the overall surgical-site infection rate in those who received more than 24 hours of antibiotics (19.5 versus 15.5 percent; p = 0.47).'] Does duration of antibiotics after microsurgical breast reconstruction change surgical infection rate?