National asset markets have become more integrated in recent years. This paper investigates the interrelationship, if any, among the stock markets in four newly industrialized economies (NIEs) in Asia. The results indicate that a significant link exists between the stock markets of Hong Kong and Singapore and those of Japan and the United States. On the other hand, the markets with severe restrictions on cross-country investing, that is, Korea and Taiwan, are not responsive to innovations in foreign markets. Finally, the United States stock market influences, but is not influenced by, the four Asian markets.