This paper investigates whether current differences in religiosity between the Dutch regions are also manifested in spatial demographic patterns. We use cluster analysis to distinguish relatively homogeneous clusters of regions, specified by religious affiliation and the frequency of churchgoing among their populations. Although the regional demographic differences are relatively modest in the Netherlands, between-clusters contrasts are consistent with the expected influence of religiosity. The cluster including the most conservative region, the so-called Bible Belt, also displays the most traditional demographic patterns. In order to differentiate the impact of religiosity from the social and economic factors, we perform stepwise regression of selected indicators of fertility, union formation and living arrangements. The frequency of churchgoing rather than the fact of belonging to a certain denomination manifested the strongest impact on the regional demographic contrasts. In case of fertility of parity four and higher, marriage rate and the proportion of young women cohabiting, churchgoing turned out to be the most important predictor of regional differentiation.