Bunan (or Gahri) is a Tibeto-Burman minority language of India. The language is spoken by between 3,500 and 4,000 speakers in Lahaul, the northernmost region of the state Himachal Pradesh. Bunan is commonly assigned to the subgroup of West Himalayish languages, which form a separate branch within the Tibeto-Burman language family. West Himalayish comprises sixteen languages, fourteen of which are spoken in the North Indian states of Himachal Pradesh and Uttarakhand to the present day. This thesis represents the most comprehensive description of the phonology and grammar of Bunan that is available to date.