The earliest stage of drug involvement is being presented with the opportunity to use drugs. During adolescence these opportunities increase. Because of the scarcity of data for the Mexican population, the aim is to estimate the prevalence of drug use opportunities among Mexican adolescents, the prevalence of drug use among those who were presented with the opportunity, and the socio-demographic correlates of both. A multistage probability survey was carried out among 12-17 year olds from Mexico City. Adolescents were administered the adolescent version of the World Mental Health Composite International Diagnostic Interview. The response rate was 71% (n=3005). Descriptive and logistic regression analyses were performed considering the multistage and weighted sample design. Twenty-nine percent has had the opportunity to try illicit drugs; of those presented with an opportunity, 18% has done so. Males, older adolescents, school drop-outs, and those whose parent has had drug problems are more likely to have been exposed to drug use opportunities while more religious adolescents are less likely. Given the chance to try drugs, older adolescents and school drop-outs are more likely to do so and those with high parental monitoring and religiosity are less likely. These results suggest that less substance use among females in Mexico may be due in part to fewer opportunities to use since females were equally likely to use drugs given the opportunity. Given the increase in opportunity among older adolescents, preventive efforts should start by age 12 and with special attention to adolescents who have dropped out of school.