582 patients scheduled for primary or revision total knee arthroplasty or total hip arthroplasty were randomized to preoperative skin preparation the night before surgery with 2% chlorhexidine gluconate-impregnated cloths or a bath with standard antibacterial soap and water. Patients were assessed for deep periprosthetic infection occurring within the first 30-90 days after surgery. Overall, the incidence of deep periprosthetic infection was significantly lower among patients who used the 2% chlorhexidine gluconate-impregnated cloths. The largest difference in infection rate was noted in the subpopulation of revision total hip arthroplasty patients.