The circumstances surrounding the admission of a patient to a critical care unit have a particularly negative effect on both the quantity and quality of sleep. Critical care nurses play an important and challenging role in the promotion of effective sleep and rest. Developing a plan of care that not only addresses the acute, life-threatening needs of patients but also promotes sleep and rest may seem impossible. This article provides a brief review of normal sleep, discusses barriers to sleep and rest in the critical care setting, and presents research-based interventions to promote sleep.