Complaints of insomnia and disordered sleep are pervasive among the elderly, and reduced total sleep time and changes in sleep architecture are considered to be normal in the aging process. Additionally, numerous medical and psychiatric disorders that are highly prevalent in the geriatric population are known to affect sleep adversely. Epidemiologic data indicate that at least 5 million older adults suffer severe disorders of sleep and that most people with severe insomnia receive no treatment for this troubling symptom. However, although the elderly comprise only about 12 percent of the American population, between 35 and 40 percent of all prescriptions for sedative hypnotics are written for people over the age of 60. Moreover, approximately 23 percent of Americans over age 85 reside in long-term care facilities, and institutionalization is an important risk factor for disordered sleep and for sedative hypnotic prescription. Consequently, the evaluation of any sedative hypnotic agent must include substantial assessment of efficacy, safety, and tolerance in geriatric patients.