They are the major sources of heterosexual and perinatal transmission. Although death was common in the IV drug use subculture prior to AIDS, death from AIDS differs significantly from death from overdose. The trauma of an AIDS diagnosis rarely leads to suicide or psychotic breaks in an IV drug user. Instead, it often leads to the desire to regain health and enter treatment easily so that the period between diagnosis need not be spent trying to hustle drugs on the street. Evidence also indicates that IV drug users in New York City are relatively well-informed about AIDS and that many have changed their behavior to reduce the risk of AIDS. AIDS has also led to changes in drug abuse treatment programs and in treatment staff attitudes. The awareness that a person may stop drug use and still die from AIDS complicates efforts to motivate drug users to avoid IV drug use. A variety of AIDS prevention programs for IV drug users have been established in the United States and Western Europe. These programs have two phases: general AIDS education and personal education in conjunction with additional means to change behavior. Further exploration is needed to determine how best to incorporate the unique aspects of AIDS into prevention programs. Chart and 52 references.