Decreases in the hours worked by trainee anaesthetists are being brought about by both the New Deal for Trainees and the European Working Time Directive. Anticipated improvements in health and safety achieved by a decrease in hours will be at the expense of training time if the amount of night-time work remains constant. This audit examined the effects of a change from a partial to a full shift system on a cohort of trainee anaesthetists working in a large district general hospital in the South-west of England. Logbook and list analyses were performed for two 10-week periods: one before and one after the decrease in hours. An 18% decrease in the number of cases done and an 11% decrease in the number of weekly training lists were found for specialist registrars. A 22% decrease in the number of cases done and a 14% decrease in the number of weekly training lists were found for senior house officers. Furthermore, a decrease of one service list per specialist registrar per week was seen, which will have implications for consultant manpower requirements.