Philosophiae Doctor - PhD / Background: Non-communicable diseases (NCDs) continue to rise in South Africa, accounting for 43% of total deaths in 2012. Smoking and a diet high in salt are among the major modifiable risk factors for NCDs that can be addressed through cost-effective policy interventions in the form of regulation or legislation and active multisectoral engagement. Population-based prevalence and mortality data are necessary for monitoring and evaluation such interventions. South Africa has developed a National Strategic Plan for NCDs but there is limited evaluation of NCD policies. Furthermore, there is a need to explore the availability of population-based data and the role that it can play to monitor interventions. Aim: The overall aim of the thesis is to assess the implementation of policies for reducing risk factors for chronic NCDs in South Africa, and to explore the role of population-based data in supporting environmental and policy approaches to prevent NCDs. The thesis will also examine whether there are differences in urban and rural settings in the implementation of tobacco control and salt reduction regulation as well as the barriers to implement the National Strategic Plan for prevention of NCDs. Methods: Multiple methods of data collection were used. A desk review of policies to address NCDs in South Africa was undertaken and semi-structured interviews with the NCD policymakers and managers in two provinces (the Eastern Cape and Western Cape) were undertaken, to explore challenges and successes of implementation of the NSP. The Cross-sectional baseline questionnaire and quantified food frequency data from the PURE study were used to determine the prevalence of smoking and the intakes of sodium and potassium in a selected urban and a rural community. Data collected using a validated community audit tool was used to assess the physical environment related to tobacco as well as questionnaire data from face-to-face interviews about perceptions about tobacco use in the urban and rural communities. Trends in mortality from tobacco related and high salt consumption related conditions together with prevalence data from national health surveys were reviewed to assess the health impact.