Purpose:Trauma is a major health problem in developing countries and worldwide which requires many resources and much time in an emergency department (ED).Although Advanced Trauma Life Support (ATLS) is the gold standard,operator dependence can affect the quality of care.The objective was to identify differences in numbers and time to lifesaving interventions,investigation,ED length of stay,and mortality between an in-house protocol and conventional practice.Methods:This was a single-center prospective non-randomized study for adult trauma patients in the ED.The trauma protocol was developed from the recent ATLS guideline.Results:Thirty-two and 41 cases were in the in-house protocol group and conventional practice group,respectively.Endotracheal intubation was done more frequently in the in-house protocol group (84％ vs.59％,p =0.03).Intercostal drainage tube insertion was done faster (6-26 min,median 11 min vs.15 -84 min,median 35 min,p =0.02) and pre-arrival notification by emergency medical service increased in the in-house protocol group (66％ vs.30％,p =0.01).Hypothermia in the operating room was found only in the conventional practice group (62％ vs.0,p =0.007) and a warm blanket was used significantly more often in the in-house protocol group (25％ vs.0,p ＜ 0.001).A directed acyclic graph with multivariate analysis was used to identify confounders.Time to Focused Assessment Sonography in Trauma was significantly shorter in the in-house protocol group (6.5-15.6 min,median 11 min,p-0.019).Conclusion:In addition to the ATLS guideline,the trauma protocol could improve trauma care by reduced time to investigation,early notification of the trauma team in pre-hospital situations,reduced incidence of hypothermia in the operating room,and increased use of a warm blanket.