This report presents findings based on a survey of drug users attending the National Drug Advisory & Treatment Centre in Jervis Street, Dublin between 1979 and 1983. This survey revealed that prior to 1979 morphine alternatives were the most widely abused drugs by those attending the clinic, but that after that the number of heroin users increased rapidly. A number of other prevalence studies in the Dublin area are referred to. The profile of the average user attending the Jervis Street centre is age 16-24 years, 4-5 years of drug use prior to contact with treatment services, early school leaving and unemployed. The extent of medical problems including hepatitis B and abscesses is outlined.