A landmark project of the Medical Research Council, the first South African National Burden of Disease (SA NBD) study, identified the underlying causes of premature mortality and morbidity experienced in South Africa in the year 2000. (1) These estimates were recently revised (2) on the basis of additional data to estimate the disability-adjusted life years (DALYs) for single causes for the first time in South Africa. DALYs are a comprehensive measure of the disease burden combining the years of life lost (YLLs) as a result of premature mortality and years lived with disability (YLDs) related to illness or injury. (3) Compared with the use of mortality as a measure of disease burden, DALYs also capture the contributions of conditions that do not result in large numbers of deaths. For example, mental health disorders have a large disability component relative to the number of deaths. The SA NBD study highlighted the fact that despite levels of uncertainty there is important information to guide public health responses to improve the health of the nation. The next step was to undertake a comparative risk assessment (CRA) to estimate the contribution made by selected risk factors, as was done globally in the World Health Report of 2002. (4) In order to protect and improve health, there is a need for much more emphasis on preventing disease and injury and on the causal determinants of health. CRA methodology, developed by the World Health Organization (WHO), is a standardised and systematic approach to estimate the contributions of risk factors, at various levels of causality to the burden of disease within a unified framework. (5) Reliable and comparable analysis of risks to health provides information on the relative contribution of individual risk factors, which can be used to guide a health sector-led response to promoting health and preventing disease and injury. Although the global assessment gives an indication of the risk factor profile that can be expected for South Africa, only a national assessment of the burden of disease and risk factor data can provide valid information for health service planning. In combination with information on the effectiveness and cost-effectiveness as well as the local applicability and appropriateness of interventions, it can contribute to the more rational use of limited resources to impact on the risk factors that determine the health of the nation.