Brazil is a country of continental dimensions with widespread regional and social inequalities. In this report, we examine the historical development and components of the Brazilian health system, focusing on the reform process during the past 40 years, including the creation of the Unified Health System. A defining characteristic of the contemporary health sector reform in Brazil is that it was driven by civil society rather than by governments, political parties, or international organisations. The advent of the Unified Health System increased access to health care for a substantial proportion of the Brazilian population, at a time when the system was becoming increasingly privatised. Much is still to be done if universal health care is to be achieved. Over the past 20 years, there have been other advances, including investments in human resources, science and technology, and primary care, and a substantial decentralisation process, widespread social participation, and growing public awareness of a right to health care. If the Brazilian health system is to overcome the challenges with which it is presently faced, strengthened political support is needed so that financing can be restructured and the roles of both the public and private sector can be redefined.