Although many studies of sedative-hypnotic drug use have been performed in Canada, there has been no national study of the use of these drugs. We have attempted to correct this deficit in our knowledge by using data from an international survey of health care utilization performed in 1968-9 and from the Canada Health Survey (1978-9), the Health Promotion Survey (1985) and the National Alcohol and Other Drugs Survey (1989) to examine sedative-hypnotic use among individuals aged 15 or more. The results suggest that the use of these drugs in Canada is about average for an industrialized society. Several socioeconomic and health care correlates of sedative-hypnotic use were found. The rate of use of these drugs was higher among women, the elderly, separated, divorced or widowed individuals, those who had a secondary school education or less, individuals with a low family income, the retired, and the unemployed. Among women, higher rates of use were reported by those whose main activity was keeping house (as compared with those who were employed outside the home) and by those who lived alone. Higher rates of use were also found for individuals who had consulted a physician or been hospitalized recently, individuals taking multiple drugs, those who scored highly on an anxiety scale, persons in whom negative feelings predominated, and those who had experienced a high frequency of psycho-physiological symptoms of anxiety and depression. From a regional point of view, the highest rates of use for women were consistently reported from Quebec, while the lowest were consistently found in the Prairie provinces. No consistent pattern was found for men.