Pretest data included an assessment of knowledge of AIDS and participation in high risk sexual and drug activities and a variety of background and demographic data. Immediately after this assessment, the participant participated in a one-on-one educational session about AIDS with a trained health educator three months later, the subjects were reinterviewed using the same measures of knowledge as in the pretest. A comparison of pretest and posttest results revealed a significant increase in knowledge after the education intervention, particularly in areas directly related to intravenous drug use such as cleaning needles with bleach, sharing cookers, and washing needles with water. Smaller increases occurred in knowledge related to sexual behavior and AIDS. The analyses also showed that knowledge among IVDUs was independent of their demographic characteristics and risk profile. 6 tables and 22 references (Author abstract modified)