The importance of strategic alliances in the form of international joint ventures (IJVs) is growing in the present international business environment where competition is on a global scale. A review of the IJV literature, especially in developing countries, shows an over-emphasis on China and the NIEs (the first tier newly-industrialising economies: Taiwan, Singapore, Hong Kong, and South Korea). To date, relatively little attention has been paid to the ASEAN4 countries (the high-performing economies of the Association of Southeast Asian Nations: Thailand, Malaysia, the Philippines, and Indonesia), even though since the 1990s this region has had one of the fastest growing economies in the world. This study provides new empirically based insights into the under-researched phenomenon of IJV formation in the South East Asian region. The study takes Thailand as an example of the ASEAN4 countries. Drawing on an unpublished official database of international joint ventures (IJVs) and a survey of managers of IJVs operating in Thailand, the study sets out to identify recent trends in Thai international joint ventures (IJVs), explore the motives and contributions of firms that participate in such IJVs and examine some of the factors that influence their performance. The study provides for the first time an in-depth analysis of a key dimension of Foreign Direct Investment (FDI) in Thailand