A cross-sectional analytical study was carried out to determine risk factors for childhood lead exposure. Blood lead levels of inner-city Sub A coloured children living in Woodstock were examined in relation to information obtained by questionnaire on environmental and social factors. The mean blood lead concentration of the population was 18 micrograms/dl. Thirteen per cent of children had blood lead levels greater than or equal to 25 micrograms/dl, the present USA 'action' level. Dusty homes and homes in a poor state of repair, over-crowding, low parental education and income, and other aspects related to family structure and socio-economic status, were associated with raised blood lead levels. It is suggested that social factors assume importance in predisposing children to lead in the environment. In particular, the over-crowded nature of the homes could have a direct bearing on the quality of the care-giving environment, providing opportunity for children's activities to go unsupervised. This could lead young children to be more exposed to accessible sources of lead associated with poor housing conditions. More attention needs to be given to examining the interaction of social and environmental factors in studies of childhood lead exposure.