"Two more Indian climbers have died on Everest yesterday," Mira Acharya, spokeswoman for Nepal's Tourism Department, told AFP, while expedition organizers confirmed the third fatality.
Kalpana Das, 52, reached the summit but died on Thursday afternoon while descending, as a huge number of climbers queued near the top of Mount Everest.
Another Indian climber, 27-year-old Nihal Bagwan, also died on his way back from the summit.
"He was stuck in the traffic for more than 12 hours and was exhausted. Sherpa guides carried him down to Camp 4 but he breathed his last there," said Keshav Paudel of Peak Promotion.
An Austrian climber died on the northern Tibet side of the mountain, his expedition organizer said.
The 65-year-old died close to the summit on his descent.
Wednesday saw an Indian and American climber die on the mountain. Last week, an Indian climber died and an Irish mountaineer is presumed dead after he slipped and fell close to the summit.
Mountaineering in Nepal has become a lucrative business since Edmund Hillary and Tenzing Norgay made the first ascent of Everest in 1953.
The Himalayan nation has issued a record 381 permits costing $11,000 each for this year's spring climbing season, triggering bottlenecks en route to the summit after poor weather cut down the number of climbing days.
Most Everest hopefuls are escorted by a Nepali guide, meaning more than 750 climbers were expected to tread the same path to the top in the current season.
At least 140 others have been granted permits to scale Everest from the northern flank in Tibet, according to expedition operators. This could take the total past last year's record of 807 people reaching the summit.
Many Himalayan mountains — including Everest — are at peak climbing season, with the window of good weather between late April and the end of May.
At least seven other climbers have died on other 8,000-meter Himalayan peaks this season, while two are missing.