This study contains a review of various methodologies that have been used by researchers in measuring, modelling and estimating international tourism demand. It includes the measures of dependent and independent variables, econometric modelling of international tourism demand and its specification. The study identifies limited use of advanced quantitative methods like differential equation based system dynamics, multi-agent model based models, game theory application, artificial intelligent and machine learning models, network modeling and graph theory. The study concludes that international tourism organization should help build research capacity on the use of these modern methods.