Arjun is the third youngest Indian to climb Mount Everest. He achieved this feat at an age of 16 years, 11 months and 18 days. He broke the record set by Krushnaa Patil of Maharashtra who climbed the summit at the age of 19. On 20 May 2011, he became the youngest climber ever to summit Lhotse, aged 17 years, 11 months and 16 days. Arjun also became the youngest to summit Mt.Manaslu on October 4, 2011 at 10 am.
Arjun Vajpai, Tshering Phinjo Sherpa and Nima Tshering Sherpa started from South Col (Camp IV 7950 m) at 10:24pm on 21 May and they reached the top of Mt. Everest at 06:33am (Kathmandu Time) on 22 May.