The present study assessed the prevalence of alcohol and “ecstasy” (MDMA) consumption in adolescents in a south area of the Community of Madrid. Attitudes toward these drugs, the adolescents’ perceived social support, the personality trait of sensation seeking (linked to drug consumption), and antisocial and/or delinquent behaviours were also studied. The results revealed a problem in the youth population regarding the consumption of these substances. Differences in trends of consumption and the related variables assessed were observed among men and women. An increase in the positive attitude toward drugs with age was also observed.