The Sundarbans, a UNESCO world heritage site, is of immense importance for its ecological and economic utilities. This paper attempts to identify, assess and classify the degree of vulnerability along the 269 km coastal stretches of Indian Sundarbans using GIS-based composite index. This study implies five physical and one social variable (geomorphology, regional elevation, absolute sea level rise, erosion-accretion, tidal range and population density) for calculating Coastal Vulnerability Index (CVI). The results indicate that nearly half of the coastlines (114 km) are under moderate to very high vulnerability regime. Inhabited mouzas like Beguakhali and Sibpur are found to be highly vulnerable on account of its high population densities, reclaimed coastline, moderate elevation, moderate erosion and medium tidal range. Lower elevation and higher rate of sea level rise were responsible for high vulnerability in uninhabited islands like Bhangadauni, Gosaba-E, Island-2 and Harin-W. Among the geomorphic categories, supra-tidal areas mostly belong to the high vulnerability category. This study provides valuable information to the decision makers and planners for understanding the problems and formulating suitable management strategies for this area. It also clarifies the major forcing factors and concludes that prioritization should be done based on relative importance, even if complete management is not feasible.