The man, who has not been named, died in hospital after falling from the Coire an t-Sneachda ridge.
A Police Scotland spokesman said: “Police in Aviemore can confirm that following the rescue of a fallen climber in the Coire an t-Sneachda area of the Cairngorms yesterday very sadly, the casualty succumbed to his injuries last night at Aberdeen Royal Infirmary.
“Police were alerted to the incident by members of the public around 12pm yesterday. The casualty was airlifted to hospital by Coastguard Helicopter R951. The man, who was in his twenties and from outwith the area, was walking/climbing alone.
“Cairngorm Mountain Rescue Team were alerted and rescue personnel from Glenmore Lodge, who were on the hill at the time, attended to the casualty until the arrival of the coastguard helicopter.
“Next of kin are aware and officers are providing support at this time. Consideration will be given to confirming the man’s identity in due course.”