Is sleep especially beneficial in times of illness? Despite the widespread use of hypnotics, the medical position on this question is equivocal, for hospital practices seem rarely designed to encourage maximum sleeping. Sleep promotion is defined as the arrangement of conditions so that patients can achieve as much sleep as possible. It is hypothesised that sleep promotion is of benefit, at least by improving patient well-being, possibly also be hastening healing processes. Some background to the hypothesis and some possible consequences of it are discussed. It is recommended that hospital procedures should be designed to encourage sleeping.