Antimicrobial therapy should never be used indiscriminately, nor can it take the place of meticulous surgical technique. Appropriate antimicrobial agents administered within the critical time period and in the recommended dosage to achieve adequate serum concentrations effectively reduce the incidence of postoperative wound and other systemic infections. The low incidence of infection and virtual absence of adverse effects strongly suggest that cephalothin-tobramycine combination therapy is a valuable adjunct in emergency surgical procedures.