Longitudinal data from a large .sample of Wisconsin men and women are used to examine the effects on fertility of religious and secular socialization, including farm upbringing. Analyses of children ever born (CEB) and of parity progression show that current religious choice is more important in explaining fertility than is religion of orientation or denomination of secondary school. The effects of current and background religion are additive, and the effect of current religion is the same for men as for women at each parity progression. Catholic religious background affects fertility primarily by increasing the likelihood of having a third or fourth child; its indirect effects on fertility operate through religious schooling and current religious affiliation. Unlike religious background, the positive influence of farm background on fertility persists among men and women, even when current farm employment is controlled.