Demographic research in sub‐Saharan Africa (SSA) has long relied on a blunt urban/rural dichotomy that may obscure important inter‐urban fertility and mortality differentials. This paper uses Demographic and Health Survey (DHS) geo‐referenced data to look beyond the simple urban/rural division by spatially locating survey clusters along an urban continuum and producing estimates of fertility and child mortality by four city size categories in West Africa. Results show a gradient in urban characteristics and demographic outcomes: the largest cities are the most advantaged and smaller cities least advantaged with respect to access to urban amenities, lower fertility and under‐5 survival rates. There is a difference in the patterns of fertility and under‐5 survival across urban categories, with fertility more linearly associated with city size while the only significant distinction for under‐5 survival in urban areas is broadly between the larger and smaller cities. Notably, the small urban ‘satellite cities’ that are adjacent to the largest cities have the most favourable outcomes of all categories. Although smaller urban areas have significantly lower fertility and child mortality than rural areas, in some cases this difference is nearly as large between the smallest and largest urban areas. These results are used to argue for the need to give greater consideration to employing an urban continuum in demographic research. Copyright © 2016 John Wiley & Sons, Ltd.