This article surveyed attending physicians on their work hours, sleep schedule, daytime sleepiness, and the perceived relation of these factors to patient safety, quality of care, and personal well-being. Physicians answered demographic and workload questions and attitudinal questions regarding work-hour limitations; the Epworth Sleepiness Scale (ESS) was used to measure subjective sleepiness, and an 18-item Impact Questionnaire was also used. Of 180 participants, 41 (23%) attending physicians manifested abnormal ESS scores (11 or greater). Private practice- and surgically-based subspecialties had higher ESS scores. Reduced sleep, but not hours worked, was associated with increased sleepiness. Sleepy physicians were more likely to associate sleep loss with medical errors and driving impairment. Sleepiness may be attenuated by education regarding consequences of insufficient sleep and institution of effective countermeasures.