Philosophiae Doctor - PhD (School of Public Health) / Access to medicines (ATM), specifically for those medicines that are related to the priority health needs of a population has been cited as a fundamental part of universal health coverage and a key element for service delivery and high-quality care. Therefore, ensuring reliable access to and appropriate use of safe, effective and affordable medicines is one of the core functions of an effective health system. With the rising demand for treatment of chronic diseases (e.g. HIV, diabetes and hypertension), ATM has increasingly received global attention. Yet as of 2011, it was estimated that at least one third of the world's population had no regular access to medicines. Globally, there is a dearth of in-depth country level evidence to influence policy responses, coupled with inadequate understanding of how pharmaceutical systems operate within broader health systems. This thesis comprises two main parts: 1) a situational analysis of the state of chronic medicines provision in the public sector in the Eastern Cape and Western Cape provinces of South Africa; and (2) an evaluation of an existing ATM model in one province. To situate this study within the ATM discourse, a conceptual framework was developed from a review of empirical and theoretical literature. The framework incorporated six ATM dimensions (availability, affordability, acceptability, accessibility, accommodation and quality) and their interplay at multiple levels including: health facility, individual, household and community levels. Then, at a health system level, the interaction of medicines (a health system building block) with other building blocks (information, financing, human resources, infrastructure and governance).