Objective: The movement to limit work hours for house staff has gained momentum in recent years. The authors set out to review the literature on work hours reform, particularly as it applies to psychiatric residency training, and to provide two different viewpoints on the controversy. Methods: The authors present the historical background of work hours reform in the United States and review recent literature about resident work hours limitations. Using a debate format, the authors discuss whether the new regulations are having a positive or negative impact on residency training in psychiatry. Results: Drs. Lomonaco and Auchincloss argue that currently-existing work hours restrictions may have unintended consequences for the health of patients and an untoward impact on residents' professional development and academic medicine's overall structure. Dr. Rasminsky argues that work hours restrictions do not go far enough in protecting residents and patients from the harmful effects of fatigue, and that our definition of professionalism needs to be reexamined in light of emerging scientific literature. Conclusion: There should be some limitation on resident work hours, with exact numbers to be determined by growing scientific knowledge about the effects of prolonged wakefulness. More study is needed, particularly in the area of psychiatric residency training.