AFI : [pyʃo] ) (15 January 1918 – 21 June 1954 ) was an Italian mountaineer and the second person to die attempting to climb K2.

Despite being one of the most promising climbers of the team, he died of high altitude pulmonary edema near camp 2.

[5] He participated with his other expedition companions in the preparation of the climbing route, the transport of materials and the establishment of the various base camps.

[5][1] Today, in light of medical progress in general and knowledge of the problems of high altitude in particular, it is believed that the cause of Mario Puchoz's death was high altitude pulmonary edema.

[7][8][9] Due to bad weather, the expedition companions could not reach Camp II until 26 July; Puchoz's body was recovered and transported to the base camp, where he was buried near Arthur Gilkey's tomb (where today the Gilkey memorial stands).