Findings indicate that users of illegal drugs, particularly narcotics, are more likely to commit property crimes than crimes against persons. Drug users are also more likely than nondrug users to commit property crime and usually reduce their commission of violent crimes after starting to use drugs. The most popular drugs of abuse are central nervous system depressants which produce a sedated, euphoric effect. However, stimulants, amphetamines, and hallucinogens can produce paranoia or distorted perceptions that result in violent behavior. The interactional context of the drug deal is very likely to produce violence in that the dealer is trying to sell low-quality drugs at high prices and the user is trying to buy high-quality drugs at the lowest prices. Homicide is a major cause of the death of drug users, and drug abusers account for a large proportion of the homicide victims in urban areas. Narcotics, cocaine, PCP, and inhalant users are disproportionately represented in crimes against persons in comparison with other types of drug users or nondrug users. These recent data may represent a new trend of increased violence among narcotics users. It is concluded that violence is a central part of drug abuse from the marketing system to the street buy and that violence is increasingly a part of the drug abuser's criminal behavior. Tables and a list of 55 references are provided. (Author abstract modified)