Despite differences in their approach to medical and nursing education, most OECD countries exercise some form of control over student intakes. In the 1980s and 1990s, several OECD countries introduced tighter student enrolment policies with an objective of cost containment. As a result, nursing and medical graduation rates decreased. Around the turn of the last century, many OECD countries found themselves facing shortages in health workers that were partly met by increasing migration flows. The contribution of foreign-trained doctors to changes in stocks of physicians is significant and has been increasing over time in many OECD countries. There are however important cross-country differences in migration of health workers that can be explained by structural and unforeseen factors. The former reflects long standing migration trends while the latter arise from unforeseen imbalances in the health labour market, largely attributable to lags between business, political and training cycles. While international recruitments of health workers can play a role in addressing short-term shortages, in a longer term perspective there is a clear choice between using migration and other policies, such as increasing domestic training or improving productivity, to address structural imbalances between supply and demand.