About 9.2 million children visit the emergency department (ED) in the US annually because of trauma and 20% experience a missed injury. Upon arriving to the hospital, physicians evaluate the child and make the ED disposition decision of whether to admit, operate or discharge. The objective of this study is to report the challenges mentioned by healthcare professionals about ED disposition decision making. We conducted 11 interviews with 12 healthcare professionals and identified 2 challenges of ED disposition decision making. The first challenge was timing of the decision; e.g., an ED nurse explained that a quick decision by physicians is important for providing timely patient care to critically ill children. The second challenge was leadership and team organization; e.g., the OR nurse and surgery resident both mentioned the need to know who to listen to so that they can understand what to do. Analyzing these challenges to ED disposition decision making can help to identify sociotechnical solutions for enhancing team situation awareness.