Using theories of distributive justice as its point of departure, this thesis deals with the tensions created by the application of the Internal Market rules to the provision of health care services within the European Union (EU). The main aim of the work is to analyse the impact of the Internal Market rules on common values and principles shared by European health systems, such as universality, accessibility, equity and solidarity. Moreover, it also aims to contribute to a more comprehensive and balanced interpretation of the role of the provision of health services in the context of the Internal Market and European Union law. The analysis developed in this thesis is conducted using the specific issue of cross-border health care, which has been chosen to demonstrate how solid values guiding European health systems can be affected by EU law and libertarian ideas. The work is divided into six chapters. The first chapter is devoted to a literature review regarding the questions of the special moral importance of health care and of theories of distributive justice used to justify the allocation of this special good among individuals. The discussion about theories of distributive justice and health care also includes the argument concerning the role of the market in health care provision. The second chapter focuses on the development of social rights of citizenship and its relationship with the welfare state. This includes the analysis of the meaning of solidarity and the concepts of European citizenship, both at national and supranational levels. The third chapter concentrates on the provision of health services at the national level. It begins by presenting a historic overview of the development of welfare services in the field of health care in Europe. Then there is an explanation of the models for financing and delivery of health care as well as their guiding principles. The fourth chapter analyses the framework of health services provision at the European level. It includes the analysis of EU legislation, such as Treaty provisions and secondary legislation, as well as the jurisprudence of the European Court of Justice (ECJ) on health services, as for example, cross-border health care and competition law cases. The fifth chapter looks at human rights law and documents in the field of health, outlining their relationship with theories of distributive justice and the provision of health care. Finally, the last chapter identifies the new paradigms and values introduced by the Internal Market rules in the field of health care, outlining their relationship with a libertarian view of health care. This chapter also examines how these new paradigms and values affect the principles of universality, accessibility, equity and solidarity at the national level, drawing conclusions about the role of the European Union in the realm of health care.