Fatigue-induced medical errors and complications spark concern in patients, clinicians, and policy makers, as documented by the Institute of Medicine report in 1999 that approximately 100,000 Americans die annually secondary to potentially avoidable injurious events. Over the last 2 decades, multiple organizations have advocated for the implementation of labor hour restrictions to redress physician in training fatigue and enhance patient safety. Advocates for duty hour caps in physician training programs cite the potential for improvements in patient safety, whereas adversaries allege that curtailing duty hours compromises medical education and readiness for solo practice. Sleep deprivation impairs multiple aspects of cognition, function, and capacity, including many aspects essential to the practice of medicine, e.g., cognizance, recollection, and dexterity. Resident physicians' traditional extended duty shifts for 24-30 consecutive hours pose significant hazards not only to patients but also to the physicians in training themselves. Burnout among physicians in training occurs commonly and results from work-related stress characterized by emotional prostration, depersonalization manifest as cynicism and detachment toward patients, and diminution of personal esteem. Curtailed shift duration correlates best with improved patient care of the strategies for managing physician fatigue. Adequate supervision of residents and medical students has the potential to improve resident education and further patient safety. Night float shifts improve resident's well-being in terms of acclimating to a consistent nocturnal schedule. Data supporting capping physician work hours demonstrates evidence of amelioration of fatigue, thereby improving physician's quality of life; evidence supporting duty hour restriction for enhancing patient safety, decreasing medical errors, and physician training, including surgical, is mixed and more nuanced.