ObjectiveTo evaluate the influence of perioperative antimicrobial prophylaxis in surgical site infection (SSI) following thyroid surgery.MethodsApplication of antimicrobial agents, healing status of surgical wound, and occurrence of healthcareassociated infection (HAI) in thyroid surgery patients before and after performing antimicrobial stewardship program were surveyed and compared. ResultsAntimicrobial use prevalence was 99.53%（211/212） in 2011 (from April to August, before stewardship intervention) and 10.89% （22/202）in 2012 (from April to August, after stewardship intervention), difference was statistically different（χ2=334.23，P＜0.001）. HAI rate was 3.77% (8/212) in 2011 and 2.97%(6/202) in 2012, and SSI rate was 1.42% (3/212) and 0.99% (2/202) respectively. There was no statistical difference in HAI and SSI rate between two groups(P>0.05).ConclusionRational perioperative antimicrobial prophylaxis enhanced significantly after antimicrobial stewardship program was performed, the reducing of perioperative antimicrobial use does not result in the increase of SSI and HAI rate.