A woman sustained head and facial injuries when she fell on the summit of Slieve Donard at about 2pm on Sunday.
The Mourne MRT and the Rescue 116 helicopter attended the scene but, at the same time, a second woman injured her knee in a separate incident as she descended the mountain.
"She was also examined by a team member before being transferred to a stretcher and airlifted by Rescue 116," a spokesman for Mourne MRT said.
"Both casualties were flown to Daisy Hill Hospital for further treatment."
Twelve members of the team had responded to the incidents and were stood down at about 4pm.