Religion is becoming an important and highly present factor in the lives of many adolescents and young adults in Brazil. In addition to creating more space for them to maintain close relationships and participate actively in a religious environment, some religions have promoted the dissemination of clearer standards and objectives, as well as punitive sanctions, with respect to many aspects of their younger followers' lives, including their sexual behavior. This article examines how religion can affect, direct and indirectly, the sexual behavior of Brazilian adolescents. The main objective of this study is to look for a connection between Christian Smith's theoretical framework, which suggests several mechanisms through which religion can influence the lives of American adolescents, and ethnographic studies conducted in Brazil, as well as quantitative works that have brought attention to social and demographic consequences of recent religious transformations. Even though there is limited empirical evidence as to how the mechanisms of religious involvement work in Brazil, this study concludes that each of Smith's pathways can also be used to explain potential effects of religion on sexual behavior of Brazilian adolescents. This research should encourage empirical studies on such effects in Brazil. Besides the importance of examining the impact of the recent transformations in Brazil religious landscape on demographic phenomena, this topic deserves further consideration from Brazilian demographers because religion is a primary socialization agent of adolescents, and sexual activity is a sphere of human behavior of high importance in its religious applicability.