Inadequate teamwork and communication are recurrent themes in studies of patient safety in the operating room. This systematic review evaluated the association between these nontechnical skills and surgeons' technical performance of procedures and found strong evidence that nontechnical skills can both positively and negatively affect technical performance. Specifically, fatigue and teamwork failures were associated with technical error, but receipt of structured feedback on procedures was associated with improved technical skills. Several successful interventions have been shown to improve patient outcomes in part by addressing deficits in nontechnical skills, such as teamwork training programs and the development of surgical checklists.