This paper examines the discursive legitimation of controversial investment projects to provide a better understanding of the ways in which corporate social responsibility is constructed in international settings. On the basis of a discursive analysis of an intense dispute between Finnish, Uruguayan and Argentinean actors over a pulp mill project in Uruguay, we develop a framework that elucidates four legitimating discourses: technocratic, societal, national-political, and global-capitalist. With this framework, our analysis helps to better understand how CSR involves discourse-ideological struggles, how CSR is embedded in international relations, and how CSR is mediatized in contemporary globalizing society. By so doing, our analysis contributes to critical studies of CSR as well as research on legitimation more generally.