Purposes: There have been many efforts to improve the service of emergency centers. In spite of these, no evidence is showing any landmark advancement of emergency services, especially in the hospital stage, exists. We need some efficient standard criteria to evaluate emergency service in the hospital stage, and a useful method might utilize the overcrowding index. We want to know the change in the overcrowding index at a regional emergency center after injury area administration. Injury area means an area in which only an assigned duty physician manages patients with injuries such as those from traffic accidents, falls, assualts, collisions, lacerations, amputations, bums, intoxication, asphyxia, drowning, animal bites, sexual assualts, etc. Methods: We started to operate an injury area in our emergency department from late 2004, and from January to June in 2004 and in 2005, we collected patients' data, age, sex, assigned department, and result from hospital order communication system to figure out overcrowding indices and result indices. We found the daily number of patients, the turnover rate, the admission rate, the ICU admission rate, the emergency operation rate, the ED stay duration, and the ED patient volume to be overcrowding indices. Also we found the withdrawal rate, the transfer rate, and mortality to be result indices. We compared these indices between 2004 to 2005 by using a t-test. Results: There was a significant increase in the daily number of visiting patients in 2005, overcrowding indices, such as the turnover rate, the admission rate, the ICU admission rate, and the emergency operation rate, also showed statistically significant increases in 2005 (P<0.001). As for the result indices, there was a noticeable decrease in the number of withdrawals (11.77/day in 2004 to 4.53/day in 2005). Conclusion: Operating an injury area in a mildly overcrowded local emergency center is beneficial. Evaluating the effect of operating an injury area and it's impact on hospital finances by conducting a similar study analyziing patients for a longer duration would be valuable.