South Africa (SA), like the rest of the Southern African Development Community, has a high prevalence of communicable diseases, an increasing non-communicable disease burden, and diverse internal and cross-border population movements. Healthy migration is good for development, but current prevention, testing and treatment responses within public health systems - particularly for chronic conditions -fail to engage with migration. Understanding of migration is poor within sectors responsible for developing appropriate responses; negative, unsupported assumptions relating to the prevalence of cross-border migration, the spread of disease, and the burden on receiving health systems prevail. In SA, public health responses fail to address internal and cross-border mobilities, and non-nationals face challenges in accessing healthcare. Of particular concern is the lack of nationally and regionally co-ordinated strategies to ensure treatment continuity for chronic conditions. Co-ordinated, evidence-informed responses to migration, mobility and health are urgently needed. These will have developmental and public health benefits for all.