Objectives. To estimate the extent of iron deficiency anaemia (IDA) among children aged 0-4 years and pregnant women aged 15-49 years, and the burden of disease attributed to IDA in South Africa in 2000. Design. The comparative risk assessment (CRA) methodology of the World Health Organization (WHO) was followed using local prevalence and burden estimates. IDA prevalence came from re-analysis of the South African Vitamin A Consultative Group study in the case of the children, and from a pooled estimate from several studies in the case of the pregnant women (haemoglobin level 11 g/dl and ferritin level 12 [micro]g/l). Monte Carlo simulation-modelling was used for the uncertainty analysis.