The difficult issues surrounding discussions of sleep, fatigue, and medical education stem from an ironic biologic truth: physicians share a common physiology with their patients, a physiology that includes an absolute need for sleep and endogenous circadian rhythms governing alertness and performance. We cannot ignore the fact that patients become ill and require medical care at all times of the day and night, but we also cannot escape the fact that providing such care requires that medical professionals, including medical trainees, be awake and functioning at times that are in conflict with their endogenous sleep and circadian physiology. Finally, we cannot avoid the reality that medical education requires long hours in a constrained number of years. Solutions to the problem of sleep and fatigue in medical education will require the active involvement of numerous parties, ranging from trainees themselves to training program directors, hospital administrators, sleep and circadian scientists, and government funding and regulatory agencies. Each of these parties can be informed by previous laboratory and field studies in a variety of operational settings. including medical environments. Education regarding the known effects of sleep. circadian rhythms, and sleep deprivation can help to elevate the general level of discourse and point to potential solutions. Empiric research addressing the effects of sleep loss on patient safety, education outcomes, and resident health is urgently needed: equally important are the development and assessment of innovative countermeasures to maximize performance and learning. Addressing the economic realities of any changes in resident work hours is an essential component of any discussion of these issues. Finally, work-hour regulations may serve as one component of improved sleep and circadian health for medical trainees. but they should not be seen as substitutes for more original solutions that rely less on enforcement and more on collaboration. By working together to address the problems of sleep and fatigue in its own trainees, the medical field can provide a valuable legacy to patients and to future generations of healthcare providers--a legacy or optimal medical education, healthy doctors, and healthy patients.