Total fertility in the Catholic countries of Southern Europe has dropped to remarkably low rates (=1.4) despite continuing low rates female labor force participation and high historic fertility. We model three ways in which religion affects the demand for children – through norms, market wages, and childrearing costs. We estimate these effects using new panel data on church attendance and clergy employment for 13 European countries from 1960 to 2000, spanning the Second Vatican Council (1962–65). Using nuns per capita as a proxy for service provision, we estimate fertility effects on the order of 300 to 400 children per nun. Moreover, nuns outperform priests as a predictor of fertility, suggesting that changes in childrearing costs dominate changes in theology and norms. Reduced church attendance also predicts fertility decline, but only for Catholics, not for Protestants. Service provision and attendance complement each other, a finding consistent with club models of religion.