This document provides guidelines for administering antibiotics before and during surgical procedures to prevent wound infections. It recommends administering antibiotics pre-operatively to achieve adequate serum levels throughout the procedure, using intravenous routes, and the highest dose of a drug active against expected microorganisms. During long procedures or those with large blood loss, it suggests redosing antibiotics that have a long half-life to maintain effective serum levels. It advises administering antibiotics for a maximum of 24 hours after a wound is closed.