The increase in number and variety of regional agreements has been accompanied by an increase in South-South cooperation (SSC) but no clear linkage between the two phenomena has been established. So far the participation in international relations of regional groups of developing nations (regionalism) has not shown significant changes in their relative power. In this article we explore if other actors, different from regional groups, have increased their power due to regionalism and what role does SSC play in that power. We support the notion that the relationship between regionalism and SSC is mediated by the global insertion of regional powers, such as Brazil, that protect and promote the objectives of their national foreign policies through cooperation toward other developing nations. Keywords: regionalism, regional powers, South-South cooperation. Received on September 17, 2013. / Accepted on October 7, 2013.