Policies on staff retention, self-sufficiency and better working conditions are becoming increasingly important driving factors in the global labour market. Health professionals often move countries in search of better opportunities; but the impact this has on EU health systems is only now coming to light. The EU-funded 'Health professional mobility in the European Union study' (HEALTH PROMETHEUS) project has published a book titled 'Health Professional Mobility and Health Systems: Evidence from 17 European Countries'. The book's case studies provide insights into the reasons for and the impacts of health mobility. Project partners also addressed individual motivation, stakeholder instruments and future mobility scenarios. Maps on the magnitude of health professional mobility were created as well. Other work included the assessment of international policy responses to health professional mobility, including the World Health Organization's (WHO) global code of practice on the international recruitment of health professionals. The team also assessed effective responses within countries, from national policies to managerial innovations. They identified and elaborated on the role of recruitment agencies, workforce planners, health workers and cross-border arrangements between countries. HEALTH PROMETHEUS found that health professional mobility affects all EU countries. It determined that staff retention initiatives could include improving working conditions and work–life balance, as well as offering career development opportunities. This information should guide policymakers and managers in the development of recruitment and retention practices.