Collaboration is one of the most frequently recommended strategies to address many global issues such as climate change, spreading diseases, and terrorism (Gray, 1989) - but, does it work for sustainable tourism? The study tested a model of inter-governmental collaboration as it relates to sustainable tourism. Three hundred and fifty nine government officers from the Greater Mekong Sub-region in Southeast Asia participated in an online survey regarding the relationship of sustainable tourism and collaboration. Structural equation modeling (SEM) analyzed survey data. Empirical results reveal a modified model with eight constructs and twenty three indicators that appears to be a better fit to the data set than the proposed model. Inter-governmental collaboration was redefined by four factors rather than eight and significantly influenced sustainable tourism. The overall fit of the modified structural equation model and the acceptable-to-high standardized loadings of the constructs suggest empirical support for a relationship between inter-governmental collaboration and sustainable tourism.