Sleep is disturbed in 90% of patients with major depression. Disordered sleep physiology may persist after clinical remission of depression, suggesting either that sleep disruption is a trait characteristic of recurrent depression or that depressed patients acquire new habits that perpetuate sleep-related problems. This article reviews the data suggesting a common pathophysiology between sleep and depression. It then focuses on a strategy for evaluating and treating sleep disruption in depressed patients. Treatment must have a conservative goal of restoring sleep quality to the pre-episode level. The treatment of sleep disruption relies primarily on optimal treatment of the depression itself. This includes evaluation and treatment of comorbid medical disorders, substance use (e.g., caffeine, alcohol), and sleep disorders (e.g., nocturnal myoclonus, sleep apnea). The effects of the different classes of antidepressant medications on sleep architecture are presented. Nonpharmacologic strategies for improving sleep, such as behavior modification, relaxation, and phototherapy, are discussed. Finally, the risks and benefits of hypnotic use in the depressed patient and a treatment algorithm for the acute and chronic use of hypnotics are considered.