Of 33 patients who underwent 49 breast implantations for reconstructive surgery, 8 (24%) patients developed implant infections. All 8 of these patients were among a subgroup of 15 having immediate breast reconstructions with tissue expander implants after simple or modified radical mastectomy (a 53% infection rate). The infection rate increased substantially when bilateral procedures involving implants were performed as opposed to unilateral implants. Nine implants were removed (an overall implant loss rate of 18%). Patients who underwent other breast reconstruction techniques (i.e., including immediate reconstruction with permanent implants or delayed reconstruction with or without tissue expanders) did not develop infection unless they had had simultaneous immediate reconstruction with a tissue expander in the contralateral breast. The most frequently isolated organism was the coagulase-negative staphylococcus. The study concludes that neither the tissue expander nor immediate reconstruction is a risk factor, but the combination may lead to an unacceptable infection rate, especially in the face of bilateral breast procedures.