During the past two decades the pace of geological work in the Himalayas has considerably increased. Of the different sectors, the Western Himalaya has been studied more extensively than the other parts. A fairly good amount of data on different aspects, including stratigraphy, sedimentology, geochemistry, geochronology and structure, has been generated from different tectonic zones of Western Himalaya. This book provides a compilation and synthesis of the post-1964 data of the Western Himalaya. The geology of the Western Himalaya is described under a tectonic zone framework, and wherever necessary, different regions are discussed separately under each tectonic zone.