Tourism is one of the fastest growing economic sectors in Southeast Asian countries, especially in countries such as Thailand and Singapore. The tourism and travel industry has been promoted as an integral part of the national development strategies for decades in these two countries. In this light, the paper identifies the causal determinants of the growth of the tourism and travel industry in Thailand and Singapore, using quarterly data from 2000-2012, under a Geweke causality framework. The empirical results suggest that for Thailand specifically, religious unrest, capturing an element of domestic instability and turbulence seems to affect international tourist arrivals significantly. In the case of Singapore, international tourist arrivals are driven by infrastructural variables covering airport facilities as well as policy variables, such as government expenditures on the tourism industry.