Background A critical appraisal of the discourse describing international medical migration around the turn of the 21 st century. Method A critical narrative review of a range of sources including grey literature, books, commentary and research reports, to trace the development and spread of specific causative models. English-language literature focussed on the Anglophone world. Findings The attribution of causative relations between the density of skilled medical workers (assumed to be linked with their migration), the provision of healthcare and population health outcomes illustrates how the global reach of biomedicine has to be understood in the context of local conditions. The need to understand migration as an aspect of uneven global development rather than a delimited issue of manpower services management is illustrated with reference to debates about 'brain-drain' of sub-Saharan Africa's healthcare professionals, task-shifting and the crisis in healthcare human resources. The widespread presumed cause of shortages of skilled healthcare staff in sub-Saharan Africa were over-determined by a compelling narrative of rich countries stealing poor countries' trained healthcare professionals. This narrative promotes medical professional interests and ignores historical patterns of underinvestment in healthcare systems and structures. Sociological theories of medicalization suggest that the international marketization of medical recruitment is a key site where the uneven global development of capital is at work. A radical reconfiguration of medical staffing along the lines of 'task-shifting' in rich and poor countries' healthcare systems alike offers one means of thinking about global equity in access to quality care.