The 67 year old was hospitalised on Tuesday (06Apr10) after falling ill while preparing for his U.K. stand-up tour.
Doctors attempted to fit tubes in his arteries to increase the flow of blood, but when the procedure failed, they advised the funnyman he will have to undergo a triple heart bypass operation.
Starr tells Britain's The Sun newspaper, "I'm due a triple heart bypass next week. It was down to stress I think."
His spokesperson adds, "He's certainly not very well and he'll need at least six months to recover."
The comedian has cancelled a string of upcoming gigs in Britain due to his condition.
Starr has been a regular on the stand-up circuit since the 1980s, after shooting to fame on U.K. TV talent contest Opportunity Knocks.