The report covers: 1) Demographic characteristics of heroin users in the target cities, including; age, sex, and race; family status and living arrangements; education levels; and income/employment. 2) Substance abuse history of heroin users, including: heroin initiation, use of other drugs, and treatment. 3) Criminal history and activity of the user groups. 4) Current drug use patterns of users, including; polydrug use, mode of administration, and habit sizes. 5) Policy implications.