The aim of this study was to determine the level of drug use and its association with criminal offenses and related conditions in a sample of mostly young males, between 12 and 17 years of age, held in a national juvenile detention center (Centro de Formación Juvenil Zurquí) en Costa Rica in the years 2006-2008. A trained technician performed the interviews using a standard questionnaire designed by the Organization of American States, Drug Abuse Control Commission and used in several Latin-American countries. The questionnaire examines the juveniles' socio-demographic background, current charges, previous and current periods of detention, criminal background, and patterns of use of several categories of drugs, age of onset, social pressure, family contention, perceptions, and knowledge of information with regard to drug use. The juveniles interviewed for this study reported mostly the use of alcohol, tobacco and a variety of illicit drugs and, in most cases, there was a close relationship between drug use and the criminal offense. While the relation between substance abuse and criminal offence is not well known, the available evidence suggests that substance use exacerbates the criminal act and precedes it due to social and economic conditions, as well as other family/community factors. Additionally, the study finds that the offenders tend to begin experimenting with substances at earlier ages than non-offenders [ABSTRACT FROM AUTHOR]