Vulnerability assessment of the ten major river basins of the Monsoon Asia-Pacific was performed by using various geospatial databases including data on nature and environment, water scarcity, hazards, demography, governance as well as social and economic development. The study looked at a combination of various issues, usually investigated in isolation form each other, on a sub-continental scale by using the river basins as the geographical entities for the study. A comparative view was taken on vulnerability and its sources in large area where more than one-third of the world’s population lives. We developed an approach which extends the river basin vulnerability assessments ‘out-of-the-water-box’, according to the current recommendations given to the water sector (Biswas,2005;World water assessment Programme, 2009). The vulnerability of river and river basins is in many ways,preconditioned by the governance situation, economic status,social matters, hazard occurrence and so forth. These should be included in the water sector vulnerability assessments more than done thus far. One such attempt was documented.