This article examines Thai policy towards Malaysia and Myanmar in the post-Cold War period and argues that bilateral relations between Thailand and these countries have deteriorated considerably. The immediate reason for the change is the collapse of structural arrangements associated with the Cold War, in particular the Indochina Security Complex and domestic political developments in Thailand and Myanmar. Whereas a number of issues like illegal migration, fishing and insurgency have contributed to the deteriorated relations, the situation has been reasonably well managed. Factors contributing to the stability of the situation include regular bilateral dialogue and exchanges as well as common membership in a number of multilateral fora like ASEAN, ARF, AFTA and APEC.