Sleep deficit is not uncommon in cardiac surgery patients, but research in this area is limited. This article examines the processes involved in sleep and how promoting these processes can optimise recovery in cardiac surgery patients. The two main parts of sleep, non-rapid eye movement and rapid eye movement, are believed to be responsible for the physical and psychological repair of the body. The combination of surgical injury, underlying disease and increased stress levels during hospitalisation for cardiac surgery increases the need for this repair. Nurses with a good understanding of sleep theories and the nursing process can use sleep and rest as an intervention to promote healing and prevent further injury after surgery.