In 1934, Günter Dyhrenfurth and his International Himalayan Expedition, including André Roch, explored Gasherbrum I and II, making it 6,250 metres (20,510 ft) up Gasherbrum II.
The first ascent came on July 7, 1956, by AustriansFritz Moravec, Josef Larch and Hans Willenpart by the Southwest Ridge. After they set up Camp I, they had to descend, and found the camp—and all their supplies and food—buried by an avalanche when they returned. Despite this, they decided to make a quick summit attempt. After opening up a route, they left Camp III on July 6. The group spent the night in a bivouac sack and reached the top at 11:30 am the next day.
1970s
In 1975, four expeditions successfully climbed Gasherbrum II, including Jean-Pierre Fresafond's French expedition, a Polish group under Janusz Onyszkiewicz, and another Polish expedition led by Wanda Rutkiewicz.
Four years later, a Chilean group claimed to have used the "normal" route to reach the top. Several others, including Reinhard Karl, Hanns Schell, and Kurt Diemberger also reached the summit.
1980s
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. 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. 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).
In August 1984, a French expedition led by Daniel Croisot, reached the summit and achieved the integral first descent by ski of Gasherbrum II, as witnessed and joined by Dominique Dock who was medical officer for the expedition. Patrice Bournat and Wim Pasquier skied the sowthwest ridge to Base Camp from 7,500 meters.
In August 1986, Gasherbrum II was successfully ascended by a Slovene expedition in only 32 hours from the base to the peak, with only 22 hours of climbing and 10 hours of rest at the altitude of 5900 m. This was by far the fastest ascent until then.
1990s
In July 1996, Jean-Christophe Lafaille climbed Gasherbrum I and II in four days, without stopping at Base Camp in between.
In 1997 Anatoli Boukreev achieved a solo speed ascent, camp ABC (5800 metres) to summit in 9 hours 30 min.
2000s
In 2006, Sebastian Haag and Benedikt Böhm climbed Gasherbrum II twice within a week. At 8:00 am on July 29, they reached the top and then skied down without abseiling or removing their skis. They rested for a few days before leaving Camp I again on August 3. They started out fast, reaching Camp IV in six hours, but 50 centimetres (20 in) of fresh snow slowed them down, and they reached the summit after over six hours of tough climbing. They descended on skis again, this time made even more dangerous by packed-down snow and the risk of avalanche. Despite this, they both made it safely back to Camp I in under 17 hours, whereas a normal expedition takes four to seven days.
Karl Unterkircher and Daniele Bernasconi, two Italians, climbed Gasherbrum II in 2007 in alpine style. They were the first to use the North Face through China. The route had been attempted a year earlier by a German–Swiss team, but they abandoned it after an avalanche. During the attempt they fixed around 1,200 metres (3,900 ft) of rope. They arrived at the summit around 8:00 pm on July 20, after spending the night in a bivouac shelter. A third member, Michele Compagnoni, grandson of Achille Compagnoni, turned back just 150 metres (490 ft) before the summit. The team reunited and descended down the normal, northwest route.
2010s
On July 22, 2011, Leila Esfandyari successfully completed the ascent to the peak but she died while descending.
On February 2, 2011, Cory Richards, Denis Urubko, and Simone Moro made the first winter ascent of Gasherbrum II. Despite being buried by a class-four avalanche, they reached the summit at 11:30 am, without supplemental oxygen or porters. Richards, who was the first American to climb an eight-thousander in winter, filmed the expedition, which he turned into the film Cold.
On July 16, 2018, Felix Berg and Adam Bielecki summited Gasherbrum II making what is arguably the first ascent of the true West Face.
2020s
In 2021, two French ski teams, including Boris Langenstein, Tiphaine Duperier, Aurelia Lanoe, and Guillaume Pierrel successfully skied Gasherbrum. 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.
On July 19, 2023, Andrzej Bargiel made the highest descent from Gasherbrum II on skis. He summitted the mountain without the use of supplementary oxygen and began his ski descent from 26,362 feet up, over 8,000m.