In January 2003, leadership of the Medicare National Surgical Infection Prevention Project hosted the Surgical Infection Prevention Guideline Writers Workgroup (SIPGWW) meeting. The objectives were to review areas of agreement among the most-recently published guidelines for surgical antimicrobial prophylaxis, to address inconsistencies, and to discuss issues not currently addressed. The participants included authors from most of the groups that have published North American guidelines for antimicrobial prophylaxis, as well as authors from several specialty colleges. Nominal group process was used to draft a consensus paper that was widely circulated for comment. The consensus positions of SIPGWW include that infusion of the first antimicrobial dose should begin within 60 min before surgical incision and that prophylactic antimicrobials should be discontinued within 24 h after the end of surgery. This advisory statement provides an overview of other issues related to antimicrobial prophylaxis, including specific suggestions regarding antimicrobial selection.