Dependence on polluting fuels (wood, coal, crop residues, animal dung, paraffin) for cooking and heating exposes countless women and young children in developing countries to elevated air pollution concentration indoors. This study explored the connection between use of polluting fuel for cooking and heating with childhood (<5 years) acute lower respiratory infections (LRIs) in South Africa. Analysis was based on data from 4679 children living in 2651 households collected during the 1998 South African Demographic and Health Survey. Cases were defined as those who experienced cough accompanied by short, rapid breathing during the two weeks prior to the survey. Logistic regression was applied to estimate the odds of suffering from acute LRI among children from households using polluting fuels in combination with electricity or liquid petroleum gas/natural gas for cooking and heating relative to those using electricity or liquid petroleum gas/natural gas exclusively, after controlling for potentially confounding factors. Two-thirds of children lived in households using polluting fuels. Nineteen percent suffered from acute LRI. After adjustment, children in households using polluting fuels in combination with electricity or liquid petroleum gas/natural gas for cooking and heating were 27% more likely to have an acute LRI event than children from households using cleaner fuels exclusively (OR 1.27; 95% CI: 1.05-1.55). Although there is potential for residual confounding despite adjustment, international evidence on indoor air pollution and acute LRIs suggests that this association may be real. As nearly half of the households in South Africa still rely on polluting fuels, the attributable risk arising from this association, if confirmed, could be substantial. It is trusted that more detailed analytical intervention studies will scrutinize these results to develop integrated intervention programmes to reduce children's exposure to air pollution emanating from cooking and heating fuels.