A cross-section of 250 youngsters enrolled in drug treatment programs in Puerto Rico were surveyed in 1991. Even though the surveyed youngsters are not intravenous drug users it was found that they have a high prevalence of behaviors considered by the Centers for Diseases Control as increasing the risk of HIV infection in youth. These behaviors include frequent experimentation with non-IV drugs, early onset of sexual behaviors (mean = 13.5 years) and drug use (mean = 13.8 years), and a high number of sexual partners (mean = 3.13) reported for the year preceding the interview. Infrequent use of contraceptives and condoms and ineffective practices to prevent STD/HIV were also reported. This subgroup of youngsters in drug treatment centers can be defined as a high risk group in need of HIV infection prevention services.