Guru Poornima (Bhadaurey Poornima) is the Holy month for the Hindus. The full moon day in the month of Bhadau (August) of the Hindu calendar is celebrated as a mark of respect to the Gurus i.e. teacher or a preacher, in the sacred memory of the great sage Vyasa, the ancient saint who compiled the four Vedas, wrote 18 Puranas, the Mahabharata and the Srimad Bhagavata. On this day several programmes and cultural performances are organized by spiritual organizations. Divine discourse and bhajan samarahos are also organized to make the day more special.

Guru Purnima is celebrated at various sacred places, especially with much grandeur at Tsomgo Lake every year. The day is celebrated here on a grand scale with devotees coming from various parts of the states. The same is celebrated at the other places of spiritual importance. All spiritual aspirants and devotees worship Vyasa in honour of his devine personage and all disciples perform puja of their respective spiritual preceptors or Gurudevas.

This festival is believed to have started centuries back. The programme is held annually and goes on for two days. It is held on the 5th day of the 6th month of Hindu calendar (Bhadau), which usually falls in the month of August as per the English Calander. The puja is mainly performed by the Hindus. On this day the spiritual is performed. The jhakri dance in traditional spiritual costumes is the prime attraction for the tourist. Devotees perform a pilgrimage to the sacred lake Tsomgo.