This chapter examines the trend towards regionalism upon stock market returns for a sample of Asian countries. We find that stock markets are becoming regionally integrated at a faster rate than globally. This finding reflects the growing co-operation between Asian countries. This study focuses upon Indonesia, Malaysia, the Philippines, South Korea, Taiwan and Thailand. These markets suffered severe contagion effects in relation to the Asian financial crisis that occurred during 1997. In addition, this study reports on the significant economic and political events that occurred in Asian economies from 1980. This study concludes that increases in liberalization coupled with stronger 'regionalism' in South East Asia contributed to the Asian financial crisis in 1997, in addition to the structural weaknesses in their financial systems. Policy setters may consider reducing the amount of intra-regional dependence in order to reduce the impact of financial crises and improve stability of the financial system.