During the past three decades, the tide in religious affiliation has rapidly shifted in Latin America. The predominance of Catholicism in the region has been challenged by the expansion of Evangelicalism and the number of individuals with no religious affiliation. Changes in Brazil’s religious landscape are explained in part by the opportunities and restrictions that government regulations place on religious organizations. Regulation shapes religious competition by changing the incentives and opportunities for religious producers (churches, preachers, revivalists, etc.) and the viable options available to religious consumers (church members). Importantly, as our description of Brazilian regulations shows, the incentives defined by regulation affect religious denominations differently, creating winners and losers. Moreover, established religious groups are often able to reshape religious regulation, reinforcing the degree to which it favors them.