This paper studies the influence of religious affiliation and frequency of church attendance in shaping preferences for family size across 13 developed countries and over five broad religious groups. The ideal number of children is higher for Conservative Protestants and Catholics, affiliations with more pronatalist teachings, than for Main-line Protestants or individuals with no religious affiliation. Religious affiliation regardless of religiosity is more significant in explaining differences in the ideal number of children for older individuals and for men than for women. With the progressive loss of influence of religious institutions in society, the degree of church attendance has become a more salient predictor of family norms, particularly for women. Church membership, independent of religiosity, exerts greater influence in demographic preferences in pluralistic societies than in countries monopolized by one religious affiliation.