Both work and social pressures have decreased the amount and quality of sleep received by individuals living in developed societies. Extended working hours contained within irregular shift patterns are common in the medical profession. Fatigue is associated with impaired clinical performance and an increased rate of road traffic accidents. An individual may not be aware of the differential effects of sleep deprivation upon individual components of neurobehavioral performance. These effects are trait-like and depend upon both genetic and acquired factors. Shift patterns and the work environment should be designed to minimize the cumulative effects of sleep deprivation. Melatonin and bright light may be beneficial, especially when used according to the phase response curve. Short naps during work breaks may improve performance and facilitate recovery. Education of staff regarding the consequences of shift work and techniques to minimize fatigue are of paramount importance.