The role of secularization in the European fertility decline has been of interest to demographers, who often explore the relationship on a macro-level or by identifying religious affiliation by proxy. However, the relationship has not been thoroughly studied on an individual level utilizing indicators of personal religious conviction and affiliation. The aim of the present article is to examine reproductive practices by religious affiliation in order to understand the impact of secularization on fertility decline. This is accomplished using event history analysis of longitudinal parish register data from Sundsvall (1860–1921) where religious affiliation is identified on a family level. Reproductive practices are analysed using cohort TFR, descriptive statistics and Cox proportional hazard regressions. Free-church affiliates had, overall, a higher probability of having another child than did affiliates to the state church. However, these differences decreased over time, and as fertility dropped throughout society free-church affiliates showed the strongest significant reduction in probability of another birth. This indicates that over time, within the free churches, ideas about respectability and restraint came to mean that birth control, in the form of abstinence within marriage, became an important practice in the formation of gendered religious identities - leading to a relatively early decrease in fertility.