Unintentional injuries represent an important health threat to the lives of children and adolescents world-wide. The epidemic of injury and resulting harm such as disability or death, are likely to be the most severe in the low- and middle-income countries of the African continent. The following paper is intended to document an area-based sampling method designed to facilitate an epidemiological study to examine injury patterns among children and adolescents in Dar es Salaam, Tanzania. We used official census data and geographic information system software to create a series of area maps for Dar es Salaam city. Then, based on these maps, we identified population clusters for sampling based on area population density.