Environmental lead poses significant health risks to small children in most western countries. However, many surveys examining the prevalence of elevated paediatric blood lead levels give insufficient attention to the geography of the major known risk factors. GIS can address the spatial variation inherent in the distribution of these risk factors, and can identify areas, streets and even individual dwellings with a high probability of environmental lead. Predictions of risk can then be validated with analysis of blood or dust samples. This analysis forms the basis for a model predicting the presence and risk of environmental lead for any city and offers a means of targeting further investigation of lead exposure, more accurately estimating the number of children at risk using small area census data and selecting areas for future sample surveys. The need to develop a cost‐efficient and accurate method of modelling lead exposure risk in childhood is a task to which GIS is clearly well suited.