Background-Non-medical use of sedatives and tranquilizers carries risks including development of abuse/dependence. Such use may correlate with psychiatric symptoms.Methods-Cross-sectional survey, the 2002-2004 National Survey on Drug Use and Health. Respondents 18 years and older (n=92,020). Bivariate and multivariable associations were investigated.Results-The prevalence of past-year non-medical use of sedatives or tranquilizers was 2.3%. Of those with non-medical use, 9.8% met criteria for abuse/dependence. On multivariable analysis, panic symptoms and elevated serious mental illness scores were associated with pastyear non-medical use. Also, the following past-year socio-demographic and substance use covariates were associated with past-year non-medical sedative or tranquilizer use: female sex, white/Hispanic/other ethnicity, criminal arrest, uninsurance, unemployment, alcohol abuse or dependence, cigarette use, illicit drug use, younger age of initiating illicit substance use, and any history of IV drug use. Among those with sedative or tranquilizer use, those with abuse/ dependence were more likely to have agoraphobic symptoms. In addition, they were more likely to be older, unmarried, have a low education level and have been arrested.Conclusions-Non-medical use of sedatives and tranquilizers is common. Furthermore, nearly 10% of those with non-medical use meet criteria for abuse/dependence. Anxiety symptoms associated with non-medical use (panic symptoms) and abuse/dependence (agoraphobia) should alert clinicians to screen for these problems and consider alternate treatment or referral.