Systems of socio-economic classification comparable to the Registrar General's Social Classification or post codes are not readily available in many developing countries. Thus health data from developing countries are usually presented without a refined geographical focus. The hierarchical urban residential classification system in Zambia was used as a socio-economic proxy to explore the relationship with mass measures of paediatric health in Lusaka, Zambia. This study shows that the Zambian urban residential classification system appears to be a valid proxy of socio-economic status, revealing residential gradients with respect to birth weight and paediatric mortality rates in Lusaka.