The concept of regionalism has been the subject of vast research. However, there have been few empirical studies of South East Asia. Although several authors have examined regionalism on a global scale (Russett 1967), the theoretical constructs have been primarily based on regionalism in Western Europe (Haas 1964). Few of these theories have been applied in the context of South East Asia. The current members of ASEAN were chosen for my research paper. (1) ASEAN includes Indonesia, Malaysia, Thailand, Singapore and the Philippines, with the later addition of Brunei in 1984. The research paper was an attempt to the following questions: • What degree of regionalism do the ASEAN countries show with regard to each variable defined as measuring regionalism. An analysis of the usefulness and limitations of each variable will be considered in the study. • What is the significance of regionalism in South East Asia, in terms of current theories in the field of Political Science/International Relations. Data was used from a variety of secondary sources including UNDEX United Nations documents, International Trade Directory and the World Handbook of Political and Social Indicators. The variables were then correlated to check the extent of regionalism in the ASEAN countries. Factor Analysis and Pearson's correlation statistic were used to determine the relationship between variables used to measure regionalism. From the study, the concept of regionalism was defined and measured by multiple indicators. The results indicated that some of the variables used to operationalize and measure regionalism may be inappropriate in an Asian setting. My study found that regionalism in terms of observable cooperation, in domestic and international policy had increased but has not reached the stage of political and economic integration among the ASEAN members. (1) ASEAN stands for the Association of South East Asian Nations. / Master of Arts