This paper evaluates an integrated water body mapping method in sub Himalayan region of Nepal with optical images of Sentinel – 2 satellites of European Space Agency. The objectives of this study is to evaluating the integrated method of water body mapping with Sentinel – 2 data and to find the optimal mapping method in Sub Himalaya region. This method extracts the information on water bodies by combining image indices and near infrared band and used slope image to remove false results.. The study results indicate that difference of indices is more accurate to map the water bodies than single index method as it enhance the contrast between water bodies and other environmental features. On the basis of the accurately mapped water bodies of the study area, this research conclude that the multi spectral images from the Sentinel images can be ideal data source for water bodies monitoring with fine spatial and temporal resolution. Although smaller water bodies with high vegetation cover cannot be detected by this method, the integrated water body mapping method is suitable for the applications multi-spectral images in this field.