This book on the mobility of health professionals reviews, analyzes, and summarizes published information and data, as well as collected interview data from stakeholders, including politicians, policymakers, health service managers, and migrant health workers. It is based on research carried out under the umbrella of the EU-funded project "Mobility of Health Professionals" (MoHProf). The partners involved in the MoHProf project gathered evidence from 25 countries regarding basic questions and knowledge gaps related to the international migration of health professionals, which involved an analysis of migration flows and evaluation of policies addressing migration. This book provides a comprehensive description and analysis of the mobility streams, the motives and driving forces behind them, and the impact on and challenges for health systems, drawing conclusions and providing recommendations.