The process of rapid urbanization in the Mekong Region represents a fundamental transformation of ecological landscapes, resource flows, livelihoods and demographics. In addition to the location of urbanization, it is these transformative processes and the critical dependence on inter-linked systems that shape the overall picture of urban disaster and climate vulnerability. By drawing on research and practical experience in two of the most rapidly urbanizing countries in the world, Thailand and Vietnam, the approach and findings have implications for understanding global patterns of urbanization. Keywords: Disaster Risk Reduction/Hazard Management; Social Vulnerability; Systems Thinking; Urban Planning