A prospective study was undertaken to evaluate 150 consecutive patients undergoing shoulder surgery at one institution. Each shoulder was prepared with one of three randomly selected solutions: ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol), DuraPrep (0.7% iodophor and 74% isopropyl alcohol), or povidone-iodine scrub and paint (0.75% iodine scrub, 1.0% iodine paint). Aerobic and anaerobic cultures were taken prior to skin preparation for the first twenty patients to determine the native bacteria around the shoulder and following skin preparation for all patients.