The dramatic rescue occurred after the man - an American visitor in his 50s - suffered a heart attack on the roof of the iconic landmark.
The man is currently on holidays in Ireland with his wife. He collapsed moments after they reached the top of the steep, narrow steps at the castle.
Staff at the tourist attraction gave first aid, while an ambulance, the fire service and a member of Blarney first responders were all on the scene within minutes.
The man was revived on the roof of the castle. A coastguard helicopter arrived less than an hour after the incident was reported to lift the man from the ramparts, bringing him to CUH where he is recovering.
His condition is described as stable.