The 1991 Substance Abuse in Arizona Survey is the fourth in a series of annual substance abuse surveys by the Arizona Criminal Justice Commission as authorized by A.R.S., Section 41-2411. The 1991 survey measured attitudes and the prevalence and frequency of substance abuse by youth in Arizona elementary schools, junior high schools, high schools, and colleges. The 1991 survey also addressed the nature and extent of drug-related gang activity in the State. The survey found that at least 6 percent of Arizona high school students claimed to be gang members in 1991; this percentage has not changed from 1990. Another 3.5 percent claimed they want to become gang members. The majority (52.8 percent) of self-reported gang members reported that gangs both sell and use illicit drugs regularly. There are many indicators in the 1991 Substance Abuse Survey that gangs have a substantial impact on the use of illicit drugs in the public schools. The Arizona Criminal Justice Commission also conducted a statewide survey of law enforcement agencies to assess the current status of street gangs and gang-related drug activity in Arizona. This report presents the results of the survey as well as findings derived from four semistructured indepth interviews conducted with law enforcement gang specialists. Findings indicate the number of identified gang members and gang- related criminal activity. Current law enforcement resources dedicated to gang activity are reported for the State level and individual counties. Appended description of the research approach and 16 tables