Refreshing sleep requires both sufficient total sleep time as well as sleep that is in synchrony with the individual's circadian rhythm. Problems with sleep organization in elderly patients typically include difficulty falling asleep, less time spent in the deeper stages of sleep, early-morning awakening and less total sleep time. Poor sleep habits such as irregular sleep-wake times and daytime napping may contribute to insomnia. Caffeine, alcohol and some medications can also interfere with sleep. Primary sleep disorders are more common in the elderly than in younger persons. Restless legs syndrome and periodic limb movement disorder can disrupt sleep and may respond to low doses of antiparkinsonian agents as well as other drugs. Sleep apnea can lead to excessive daytime sleepiness. Evaluation of sleep problems in the elderly includes careful screening for poor sleep habits and other factors that may be contributing to the sleep problem. Formal sleep studies may be needed when a primary sleep disorder is suspected or marked daytime dysfunction is noted. Therapy with a benzodiazepine receptor agonist may be indicated after careful evaluation.