Improving the performance of Emergency Room (ER) has become a major concern for both healthcare professionals and researchers. ER patients' length of stay is one of the most important indicators for performance monitoring as well as improvement. The main objective of this study is to evaluate the effects of enhancing ER information accessibility of nurses, through a special ER nurses training program, on reducing patients' length of stay. Data on 5,769 ER encounters were retrospectively retrieved and analyzed to compare ER length of stay and related intervals of the first quarter of 2015, after implementing the training program, to the first quarter of 2014, before implementing the program. There was a 25.5% improvement on "Arrival to Triage" interval, 17.7% improvement on "Triage to ER Bed", 16.1% improvement on "ER Bed Assigned to Doctor Examination" and 13.2% improvement on "Doctor Examination to Discharge" interval. The total ER length of stay was improved by 13.7%.