IT is viewed as integral to achieving substantial quality and efficiency improvements in U.S. healthcare delivery and management. A key idea behind these suggestions is the use of IT to support knowledge management to enhance and facilitate evidence-based clinical decisionmaking. Yet, it is not clear to what extent IT-enabled knowledge management systems will be effective for physicians who make complex clinical decisions under time pressure and high degree of uncertainty. To address this gap, we are conducting a field study to examine the impact of ITenabled knowledge management systems in an emergency department at a major university hospital in the Southeast region of the US. The preliminary results of our analyses show that the use of IT-enabled knowledge application tools indeed influence the healthcare professional’s clinical decision-making behaviors, which in turn influence the outcome of patient care.