ObjectiveTo analyze the current situation of antimicrobial agents using in day surgery patients to guide the rational use of antimicrobial agents in day surgery.MethodsThe day surgery performed in Day Surgery Center of Xiangya Hospital of Central South University from June 2016 to September 2017 was selected. We retrospectively collected and analyzed patients’ hospitalization data and return visit data, statistically analyzed their use of antimicrobial agents, explored whether there was an unreasonable phenomenon in the use of antimicrobial agents, and analyzed the reasons.ResultsThere were 4 054 surgeries included in this study, and 1 293 patients using antimicrobial agents, the use rate of antimicrobial agents in day surgery patients reached 31.89%. Aseptic, clean-contaminated, contaminated and dirty surgery accounted for 12.22%, 65.20%, 7.27%, and 15.31% separately. Whether the application of antimicrobial agents in aseptic surgery patients had no effect on the outcome of the incision (P=0.073). The most common type of antimicrobial agents used by patients are cephalosporins (57.50%), mainly used as single drugs (97.91%) and mostly oral used in patients’ home. Most of the sources of antimicrobial agents were purchased by patients after they were discharged from the hospital (65.43%). The antimicrobial agents more used by Stemmatological Department (23.98%), Ear/Nose/Throat Department (22.58%) and Obstetrics and Gynecology Department (22.51%). The average used time of antimicrobial agents was (5.37±1.86) days, and 7.42% of patients still had surgical site infections after the use of prophylactic antimicrobial agents, most of them from General Surgery Department.ConclusionsThe unreasonable phenomena in the use of antimicrobial agents in patients with day surgery include: a high proportion of preventive medications for clean-contamination surgery, a high level of initial medication, and most patients take oral medications at home and lack of guidance, and long medication time. There is an urgent need for scientific guidance on the use of antimicrobial agents for patients undergoing day surgery.