Effective teamwork is one of the most important aspects of providing care in today's healthcare system. Human factors researchers and practitioners alike are regularly asked to evaluate and improve teamwork within many complex and varied care settings. This invited symposium will include experts in teamwork theory and clinical application within different care environments, with the specific goal of discussing methods to better understand teams and their functions for both research and quality improvement. Methods include validated behavioural rating systems, data mining from electronic medical records, interviews, augmented hierarchical task analysis, and video analysis, all of which have been used to better understand team performance in various clinical tasks. In addition, the symposium will focus on work outside of the operating room, and in other areas of acute care, specifically the post-anaesthesia care unit, the trauma bay, the intensive care unit, and outpatient clinic settings.