The treatment of sleep-related illness in older patients must be undertaken with an appreciation of the physiologic changes associated with aging. Insomnia is common among older people. When it occurs secondary to another medical condition, treatment of the underlying disorder is imperative. Benzodiazepines, although potentially effective, must be used with care and in conservative doses. Daytime sedation, a common side effect, may limit use of benzodiazepines. Newer non-benzodiazepine drugs appear to be promising. Rapid eye movement (REM) sleep behaviour disorder can be treated with clonazepam, levodopa-carbidopa or newer dopaminergic agents such as pramipexole. Sleep hygiene is important to patients with narcolepsy. Excessive daytime sleepiness can be treated with central stimulants; cataplexy may be improved with an antidepressant. Restless legs syndrome and periodic leg-movement disorder are treated with benzodiazepines or dopaminergic agents such as levodopa-carbidopa and, more recently, newer dopamine agonists. Treatment of obstructive sleep apnea includes weight reduction and proper sleep positioning (on one's side), but may frequently necessitate the use of a continuous positive air-pressure (CPAP) device. When used regularly, CPAP machines are very effective in reducing daytime fatigue and the sequelae of untreated obstructive sleep apnea.