[4] The mountain was first climbed on July 7, 1956, by an Austrian expedition which included Fritz Moravec, Josef Larch, and Hans Willenpart.

Contrary to popular belief, it does not mean "shining wall", which is how Sir William Martin Conway described nearby Gasherbrum IV on an 1892 exploration.

[17][18] The first ascent came on July 7, 1956, by Austrians Fritz Moravec, Josef Larch and Hans Willenpart by the Southwest Ridge.

[17] Swiss Mountaineers Romolo Nottaris and Tiziano Zünd were the first to reach the summit in alpine style on August 3, 1981.

On July 24, 1982, Reinhold Messner, along with Nazir Sabir and Sher Khan, climbed the peak via the Southwest Ridge.

[17][21] During the ascent, Messner discovered the body of a previously missing Austrian mountaineer, whom he buried two years later at the G I – G II crossing.

[22] He wrote of his climb of Gasherbrum II in the book 3 x 8000: My Great Year in the Himalaya (German: 3 x 8000: Mein grosses Himalaja-Jahr).

[26] In 1997 Anatoli Boukreev achieved a solo speed ascent, camp ABC (5800 metres) to summit in 9 hours 30 min.

On February 2, 2011, Cory Richards, Denis Urubko, and Simone Moro made the first winter ascent of Gasherbrum II.

[31][32] On July 16, 2018, Felix Berg and Adam Bielecki summited Gasherbrum II making what is arguably the first ascent of the true West Face.

[34] On July 18, 2023, Hugo Ayaviri climbed Gasherbrum II without oxygen, the fourth 8000’er in his quest to be the first Bolivian to summit all fourteen 8000m peaks.