Historical Germany represents a perfect laboratory for studying interregional demographic differences, yet the historical family structures in this part of the European continent remain largely unexplored. This study documents the variability of living arrangements using an aggregate measure of household complexity based on published statistics of the German census of 1885. Descriptive methods and spatially sensitive modelling techniques are applied to these data in order to examine existing hypotheses on the determinants of household complexity in historical Europe. We investigate how regional variation in agricultural structures and employment, inheritance practices, ethnic background, and other sociodemographic characteristics relate to regional variation in household structures. Our results show that areas with low levels of household complexity were concentrated in south-western and southern Germany, while areas with high levels of complexity were mostly situated in the north and north-east. The supposedly decisive socioeconomic and cultural macro-regional differences that are known to have existed in late nineteenth-century Germany were at most only weakly associated with existing spatial patterns of household complexity. These results tend to support Ruggles’ (2009) view that spatial variation in household structures is mostly linked to the degree of employment in agriculture and demographic characteristics.