The present study is a preliminary taxonomic survey of diatom assemblages from one of the highest mountain ranges in the Western Himalayas – Ladakh. 37 samples were collected from 19 different sampling sites at altitudes ranging from 3100–4552 amsl. The diatom communities were representative of habitats such as lakes, streams, and hot springs from high altitudes. The dominant diatoms are studied using light microscopy and identified using valve morphometrics. The study enlists a total of 74 taxa belonging to 40 genera along with photomicrographic plates. Commonly-found species of high-altitude hot springs habitats were