In the backdrop of the recent economic crisis in the European Union, this study attempts to assess the degree of regional integration and the suitability of a monetary union in the East and South-East Asian (ESEA) region. For this purpose, we analyse the issue in a variety of ways. First, a long-run linkage of real output of the countries is tested using the cointegration analysis. Results suggest that real output of most of the countries in the region is cointegrated and move together in the long-run. To analyse the issue in detail, we focus on the impact of three different shocks, namely global, regional and country-specific, on real output of the countries. Results of impulse response and variance decomposition analysis reveal that regional shocks do not dominate in the sample countries, which is an indication of unfavourable condition to form an optimal currency area (OCA) in the region. These results are further confirmed by the outcome of computation of the modified Bayoumi and Eichengreen’s Indices. Finally, we employ the concept of Generalized Purchasing Power Parity (G-PPP), which however reveals that the bilateral real exchange rate of ESEA countries move together in the long-run and share a common stochastic trend, which in turn provides some empirical support for an OCA in the region.