At the dawn of the new millennium, not only have poor countries’ health needs not diminished, but they seem to have worsened due to a complex interplay among many factors that result in huge inequities within and between countries. This critical situation calls international development cooperation into question once again and prompts new thinking. In this process, South-South cooperation has steadily gained importance. At the start of the 21st century, international – particularly South-South – cooperation has come to occupy a strategic place in Brazilian foreign policy, and health is a priority item on this agenda. This paper examines the Brazilian conception of horizontal “structural cooperation in health”. It presents a brief historical review of international development cooperation and health cooperation, explores the concept of “structural cooperation in health”, and discusses the Brazilian proposal formulated over the past decade and its implementation to date. This Brazilian approach centers on the concept of “capacity building for development”, but innovates in two respects: by integrating human resource development with organisational and institutional development and by breaking with the traditional passive transfer of knowledge and technology. It is still early to evaluate its impact, but this cooperation has been implemented on the basis of five interrelated strategic, political and technical considerations: (a) priority for horizontal cooperation; (b) focus on developing health capabilities; (c) coordinated initiatives in the regional context; (d) strong involvement of health ministers in building strategic and political consensus; and (e) encouraging partnership between ministries of health and foreign relations.