The drivers of food insecurity in rapidly growing urban areas of the Global South are receiving more research and policy attention, but the precise connections between urbanization, urban food security and migration are still largely unexplored. In particular, the levels and causes of food insecurity amongst new migrants to the city have received little consideration. This is in marked contrast to the literature on the food security experience of new immigrants from the South in European and North American cities. This paper aims to contribute to the literature on urban food security in the South by focusing on the case of Zimbabwean migrants in South African cities and discussing the results of a household survey of migrants in Cape Town and Johannesburg. The survey showed extremely high levels of food insecurity and low dietary diversity amongst migrants, which are attributable to the difficulties of accessing regular incomes and the other demands on household income. Most migrants are also members of multi-spatial households and have obligations to support household members in Zimbabwe. Although migration may improve the food security of the multi-spatial household as a whole, it is also a factor in explaining the high levels of insecurity by migrants in the city.