The sharing of health data advances knowledge, fosters innovation, and promotes evidence‐based decision‐making. This practice involves using existing data for collaborative research or for purposes other than those for which it was originally collected. In South Africa, the secondary use of health data has significant potential to inform policy decisions, advance scientific research, and address societal challenges. However, the use of health data for secondary purposes in the public health sector is faced with several challenges and legal complexities. This article (...) examines these challenges and legal dimensions, with particular attention to the regulatory framework governing health data in South Africa, including issues of consent, privacy, data ownership, and intellectual property rights. Understanding these legal considerations enables stakeholders to navigate the complexities of secondary data use in an ethically sound and legally compliant manner. (shrink)