PURPOSE: The primary goal of wound management is to avoid infection. Wounds in all patients presenting to the Emergency Department are contaminated with bacteria. Despite this, there is a low incidence of infection. Unfortunately, physicians continue to use antimicrobial agents indiscriminately. The authors intended to determine the effect of selective antimicrobial agents and the indications for appropriate antimicrobial agent use in traumatic simple wounds. METHODS: This prospective study was performed from Jul. 2005 to Aug. 2005. A pilot study had been performed from Nov. 2003 to Jul. 2004 at the Ewha Woman's University Mokdong Hospital. Structured data sheets were completed at the times of the patient's visits to the Emergency Department and to the Outpatient Department for follow-up. Infection was determined at the time of follow-up. The indications of antimicrobial agent use are immunocompromised patients, wounds contaminated for 3 hours or longer, devitalized tissue, and extremity wounds except hand wounds caused by sharp objects. RESULTS: The study enrolled 216 injured patients. The general characteristics of patients and wounds between the two groups were not significantly different. The antimicrobial agent use and infection rate of the pilot study were 227 cases (90.4%) and 10 cases (4.0%), and those of this study were 100 cases (46.3%) and 9 cases (4.1%). In this study, antibiotic use was reduced to almost half compared with the previous study, but the infection rate was similar (p<0.001). CONCLUSION: Rational use of antimicrobial agents in simple wounds reduced the use of antimicrobial agents in the Emergency Department without increasing the infection rate.