Surgical antimicrobial prophylaxis (AMP) is an effective measure to prevent surgical site infections. To determine the quality and availability of local guidelines for AMP, a survey was conducted in the public hospitals of a Northern Italian region. The guidelines for "Antimicrobial Prophylaxis in Surgery" by the Scottish Intercollegiate Guidelines Network (SIGN) were used as a standard by which the quality of the local guidelines was compared. The coverage of surgical specialities by local AMP guidelines was 93.1% for hospitals where guidelines had been developed at hospital level and 47% for hospitals where guidelines had been developed by individual surgical departments. Local guidelines recommended AMP for most surgical procedures (96%), including procedures with evidence against the use of antimicrobial prophylaxis (87% of these procedures). Only 8% of all procedure-specific guidelines (PSG) recommended an incorrect timing of AMP (not administering AMP at the induction of anaesthesia), while 41% recommended an incorrect duration (additional antimicrobial doses after completion of the surgical operation). This survey showed that having written protocols at local level does not necessarily mean they comply with available scientific evidence. Thus, the quality of local guidelines needs to be improved.