ABSTRACTPostoperative surgical site infections contribute significantly to increased patient morbidity and mortality rates and unnecessary hospital costs. Effective and efficient preoperative patient skin preparation is an important perioperative nursing intervention that decreases the number of wound contaminants and reduces the risks for postoperative surgical site infections. This study examined the effectiveness and time and material costs of two preoperative patient skin prep methods (ie, isopropyl alcohol prep/iodophor‐impregnated adhesive drape method, iodophor scrub and paint prep/plain adhesive drape method). The isopropyl alcohol prep/iodophor‐impregnated adhesive drape method clinically was as effective as the iodophor scrub and paint prep/plain adhesive drape method, more cost‐effective when time and materials were compared, and less cost‐effective when materidls alone were compared. To make appropriate decisions about the use of preoperative patient skin prep methods, perioperative nurse managers and staff members need to examine and determine whether costs in time or materials have the greater impact on their surgical settings. AORN J 62 (Sept 1995) 393–402.