Researches have emphasized religiosity as a protective factor against drug use although the mechanism through which it occurs is still unknown. This article aims to explore religious beliefs that could prevent drug use among youth. Three sources of qualitative data were used: participant observation in 21 religious institutions, semistructured interviews of 37 religious leaders, and 6 focus groups comprised of 55 religious drug-naive youths. The young people's discourses and the sermons of religious leaders revealed that conceptions about drugs were based on media content, with little religious or scientific context. Catholics and Spiritists considered the consumption of licit drugs less harmful than that of illicit ones and were especially tolerant of the use of alcohol. Protestants were more emphatic when describing all drugs as being harmful to one's health. Findings suggest that young people who practice a religion invoke several religious concepts to justify their choice for not using drugs, and they attribute this position more to the family legacy than to their own religiosity. Thus youths' antidrug position was more reflective of family values than religious beliefs. (Contains 1 note.)