The relations among sociodemographic factors, health status, and use of prescribed sleeping pills and tranquilizers are examined. The data are from the Rand Health Insurance Experiment, which has a random sample of the nonaged, noninstitutionalized, civilian population in six U.S. sites. Information on sociodemographic factors, health status, and the use of prescribed psychotropic drugs during the previous 3 months was obtained from self-report questionnaires collected at enrollment. Mental and physical health status have large independent and significant effects on the probability of use of both prescribed tranquilizers (P