Sleep complaints are common in geriatric patients. The clinician's first task is to separate sleep problems originating in the physiologic changes of aging from those originating in pathological processes. Normal elderly persons have greater difficulty falling asleep and staying asleep, compared with younger persons, and sleep is qualitatively more shallow with more involuntary movements and abnormal breathing. Sleep complaints reach a pathological level as elders begin to experience deterioration of function during their period of normal wakefulness, manifested as excessive sleepiness, concentration deficits, and mood changes, or the emergence of bizarre or dangerous behavior during sleep. Sleep disorders are associated with excess physical and psychiatric morbidity and are treatable. An approach focused on sleep-related syndromes is a useful basis for rational treatment, and the treatment of many sleep disorders can be provided without expensive sleep laboratory testing.