This article reviews research on the relationship between illicit drug use and crime conducted since 1980. Significant advances are noted in studies of the crime of known drug abusers and in studies of the drug use of individuals processed by the criminal justice system. Major conclusions supported by the results of studies of the criminal activity of narcotic abusers are that both a higher prevalence and higher rates of crime are associated with more frequent use of heroin and/or cocaine, although addicts vary with regard to the type, amount, and severity of crime they commit. Rates of lifetime and recent illicit drug use, particularly the use of cocaine, among prisoners, parolees, probationers, and arrestees are high compared to the general population. Issues discussed include the etiology of drug abuse, the effects of treatment and criminal justice interventions on drug use and crime, and drug-related violence.