Teamwork has become a major focus in healthcare. In part, this is the result of the Institute of Medicine report entitled To Err Is Human: Building a Safer Health System, which details the high rate of preventable medical errors, many of which are the result of dysfunctional or nonexistent teamwork. It has been proposed that a healthcare system that supports effective teamwork can improve the quality of patient care and reduce workload issues that cause burnout among healthcare professionals. Few clear guidelines exist to help guide the implementation of all these recommendations in healthcare settings. In general, training programs designed to improve team skills are a new concept for medicine, particularly for physicians who are trained largely to be self-sufficient and individually responsible for their actions. Outside of healthcare, research has shown that teams working together in high-risk and high-intensity work environments make fewer mistakes than individuals. This evidence originates from commercial aviation, the military, firefighting, and rapid-response police activities. Commercial aviation, an industry in which mistakes can result in unacceptable loss, has been at the forefront of risk reduction through teamwork training. The importance of teamwork has been recognized by some in the healthcare industry who have begun to develop their own specialty-driven programs. The purpose of this review is to discuss the current literature on teaching about teamwork in undergraduate medical education. We describe the science of teams, analyze the work in team training that has been done in other fields, and assess what work has been done in other fields about the importance of team training (ie, aviation, nonmedical education, and business). Additionally, it is vital to assess what work has already been done in medicine to advance the skills required for effective teamwork. Much of this work has been done in fields in which medical professionals deal with crisis situations (ie, anesthesia, trauma, and labor and delivery). We describe the current programs for teaching medical students these essential skills and what recommendations have been made about the best ways to introduce teaching this skill set into the curriculum. Finally, we include a review on assessing teamwork because one cannot teach team training without implementing an assessment to ensure that the skills are being learned.