Infectious disease alters sleep patterns in rabbits, but the recuperative value of enhanced sleep during infectious disease has not been experimentally verified. To evaluate the relationship between specific sleep patterns and the clinical response to infectious disease, we classified sleep patterns in rabbits inoculated with E. coli, S. aureus, or C. albicans on the basis of the duration of the period of enhanced sleep. Patterns characterized by a long period of enhanced sleep were associated with a more favorable prognosis and less severe clinical signs than were patterns characterized by relatively short periods of enhanced sleep followed by prolonged sleep suppression. A contrasting analysis of these data indicated that animals that eventually died demonstrated reduced sleep compared to rabbits that survived the infection. These observations are consistent with the hypothesis that dynamic changes in sleep over the course of an infectious disease aid in recuperation.