This study applies Porter's diamond framework, which tries to identify the sources of international competitive advantage, to Turkey. The major objective is to contribute towards an improvement of this framework, and thus towards a better understanding of the sources of competitive advantage. The study also aims to shed some light on the competitive structure of the Turkish industry. The findings are generally supportive of Porter, meaning that the diamond framework works in a developing country setting. The results suggest, however, some major areas in the framework (especially domestic rivalry and the role of government) where one or more of the Turkish case studies contradict the Porter hypothesis. (C) 2002 Elsevier Science Inc. All rights reserved.