The pediatric emergency department (ED) is a complex environment where physicians perform multiple tasks under intense time pressure and are interrupted more often than in any other hospital department. Documentation is one task that consumes a majority of physicians' time. Despite the important implications of documentation for diagnosis, communication, and billing, we know very little about the role of documentation within physician workflow. Using a quasi-ethnographic approach to observe and record documentation and interruptions in real time, researchers followed 11 pediatric ED physicians for a total of 23 8-hour shifts. A systems-approach analysis was used to examine the factors that most strongly shape performance including communication, tasks, technology, organization, and environment. Possible barriers to documentation within workflow were also discovered and recommendations were given. This research sheds light on workflow in technology-driven environments and the impact of workload and interruptions on physician documentation.