Urban food security is a significant development challenge in sub-Saharan Africa. However, the field is current- ly under-researched and under-theorized. Urban food insecurity, where it is considered, has been viewed through a development studies lens that views food insecurity as a household-scale prob- lem. There has been significant focus on food deserts in devel- oped countries as one way of engaging with such insecurity. The food deserts research views food insecurity through a social ex- clusion and food justice lens. This article introduces the food de- sert concept to provide a conceptual tool to begin to understand the spatial determinants of urban food insecurity, which are not well captured by the existing framings of food security in the region. Using data from a 2008 household food security survey conduct- ed in Cape Town, the paper highlights gaps in the food deserts ap- proach, most significantly its neglect of non-market sources of food and of household decision-making processes. The paper therefore concludes by suggesting a new approach which takes the house- hold's assets, abilities and decision-making as the starting point and overlays this with the market and non-market foodscapes accessed by these households.