Urbanization is an important demographic phenomenon in sub-Saharan Africa, and rural-urban migration remains a major contributor to urban growth. In a context of sustained economic recession, these demographic processes have been associated with a rise in urban poverty and ill health. Developments in health service provision need to reflect new needs arising from demographic and disease ecology change. In malaria-endemic coastal Kenya, we compared lifelong rural (n = 248) and urban resident (n = 284) Mijikenda mothers' responses to childhood fevers. Despite marked differences between the rural and urban study areas in demographic structure and physical access to biomedical services, rural and urban mothers' treatment-seeking patterns were similar: most mothers sought only biomedical treatment (88%). Shop-bought medicines were used first or only in 69% of the rural and urban fevers that were treated, and government or private clinics were contacted in 49%. A higher proportion of urban informal vendors stocked prescription-only drugs, and urban mothers more likely to contact a private than a government facility. We conclude that improving self-treatment has enormous potential to reduce morbidity and mortality in low-income urban areas, as has frequently been argued for rural areas. However, because of the underlying socio-economic, cultural and structural differences between rural and urban areas, rural approaches to tackle this may have to be modified in urban environments.