Findings are reported from a 1981 cross-national survey of the use of anti-anxiety/sedative medications by adults in the general population of the United States and 10 Western European countries. Representative national samples in the 11 countries were asked a standard set of questions about their use of these medications during the preceding 12 months. Data were obtained by personal interview in the course of a household visit. The number of persons interviewed ranged from 1486 to 2018. The data provide comparable estimates of past-year prevalence of use-the proportion of the population who took these medications one or more times, and duration of use-and the proportion of the population who took these medications daily for various lengths of time. Rates for past-year prevalence of use varied from 17.6% in Belgium to 7.4% in the Netherlands. The United States at 12.9% was in the middle of the distribution. There was wide variation among countries in the prevalence of long-term and short-term use, but regular daily use for 3 months or less was the predominant pattern in 10 of the 11 countries surveyed. Past-year prevalence rates were much higher for women than for men in every country surveyed. At the national level, the data show that simple past-year prevalence rates and durational parameters of use are relatively independent.