The choppers' rotor blades struck each other as they were trying to land just below Mount Everest's base camp at Pheriche village on Tuesday morning.
The 47-year-old man who died at the scene was a passenger aboard a Fishtail Air helicopter.
The other passenger, a New Zealander, was airlifted to Kathmandu for treatment.
A Nepali pilot suffered injuries but was treated locally.
The total number of people on the two helicopters wasn't clear.
The aircraft were ferrying trekkers who had been hiking up to Everest base camp during Nepal's popular trekking season.
There are no roads on Everest, and helicopters are the only way to bring down trekkers and guides who become sick or exhausted in the cold and high altitude.
Nepal, home to eight of the world's 14 highest peaks, is in its autumn season, which is considered one of the best times for trekking and hiking, including in the Everest region.
The Mount Everest base camp trek lasts up to two weeks and goes from the only airstrip in the area at Lukla to the camp, which is situated at 5300 meters (17,380 feet) altitude.
Pheriche village is at 4200 meters (13,780 feet) altitude.
Nepal has had dozens of aviation accidents in recent years, largely attributed to its challenging terrain and poor aviation safety.
With AP
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