The European Commission promotes geographical mobility as a strategy to reduce discrepancies between supply and demand in European labour markets. While migration levels are low within and across EU Member States by comparison with other OECD regions, the proportion of EU migrants working in the EU is rising. EU-level efforts to promote mobility are sometimes overshadowed at national level by concerns over the potential negative effects of migrant inflows including the undercutting of local wage rates, the abuse of welfare systems and the financial burden that inactive migrants may put on welfare systems. This report documents the current picture of labour mobility within the EU, and puts forward some policy pointers for facilitating the flow of workers while minimising abuses of the migrant worker system and making for smoother transitions for migrant workers. An executive summary is available.