Seattle-bound United flight 1603, which took off from Houston with 161 passengers on board, landed safely and the pilot was rushed to a local hospital, Boise Airport spokeswoman Patti Miller said, reported Reuters.
The pilot, whose name was not released, died as a result of the medical emergency, United spokeswoman Christen David said on Friday.
"I am sad to confirm that our co-worker passed away last night," she said. "Our thoughts are with his family at this time."
The Boeing 737 aircraft later continued on to Seattle, landing just after midnight local time, David said.