Since data relevant to the drug-violence nexus are not specified in major national data bases, a review of existing knowledge on drug-related violence must chiefly rely on local studies. Such studies indicate that drugs and violent crime are related under three models: the psychopharmacological, the economic-compulsive, and systemic. The psychopharmacological model suggests that some persons who ingest certain drugs may become excitable, irrational, and violent. Barbiturates are most likely to produce violent behavior. The economic-compulsive model reasons that some drug users engage in violent property crime to support costly drug use, and the systemic model indicates that violence is intrinsic to involvement with any illicit substance. Ongoing research hypothesizes that a greater proportion of drug-related violent events perpetrated by women result from psychopharmacological effects. Women are apparently less likely than men to commit economic-compulsive or systemic violent acts. Future studies must move beyond simple correlations between drug use and violence to reveal how drugs contribute to the process of violence. 8 notes and 114 references.