The climbers, identified as 51-year-old Giuseppe Sabbatini and 43-year-old David Remigio, had been climbing the Corno Piccolo summit of the mountain using ice axes and crampons when the avalanche struck, Ansa reported.
The pair fell 300 metres to their deaths at around 1.00pm on Sunday at an altitude of around 2,400 metres in Prati di Tivo, in the Teramo province of Abruzzo.
The avalanche is believed to have been caused either by the increased temperatures in the area or by a group of mountaineers further up the mountain.
The two men were pronounced dead at the scene on Sunday afternoon and their bodies recovered by staff from the National Mountain Rescue.
Sabbatini, who was married with a daughter, was a mountain guide and volunteer with the CNSAS (National Mountain Rescue Corps) and a rescue helicopter technician.
Just minutes before the accident Sabbatini posted a photo on Facebook showing himself smiling at the top of the mountain.
In a statement issued on Sunday afternoon, the CNSAS expressed its “deep sorrow and mourning for the sudden loss of Giuseppe (Pino) Sabbatini”.
The climbers are just the latest victims in the area this winter. Less than a month ago Sabbatini himself assisted in a five-day rescue operation for two young climbers, Giovanni De Giorgi and Massimiliano Cassa, who also died while climbing the mountain.
Gran Sasso is located in the Gran Sasso e Monti della Laga National Park, which holds the highest mountains in continental Italy south of the Alps.