Initially it was thought he suffering from fatigue following another Tour de France where he now works as an ambassador for yellow-jersey sponsor Crédit Lyonnais.
However, his health deteriorated and he died at 2am on Wednesday morning in Saint-Léonard-de-Noblat.
'Poulidor the unlucky? No, I had a lot of luck' - a great in his own words
In his decorated career, the cycling icon won the Vuelta a Espana in 1964, two classics with Milan-San Remo (1961) and the Flèche Wallonne (1963). He achieved the double in Paris-Nice (1972, 1973) and Dauphiné in 1966 and 1969.
His eight times on the podium at Le Tour are the most of any rider.
'CYCLING WORLD LOSES A MONUMENT, AN ICON'
Eddy Merckx says he has been hit hard by the death of his old rival and good friend.
Merckx raced Poulidor at the Tour de France five times between 1969 and 1975. The Belgian finishing on the podium three times ahead of Poulidor.
"The cycling world loses a monument, an icon," Merckx told Het Nieuwsblad.
"You can't imagine how loved Poupou was in France – every year I saw that at the Tour. France loved his charm.
"We have Jacques Anquetil and Bernard Hinault as the unforgettable riders in France, but don't hesitate to put Raymond Poulidor in the picture.
"[He is] maybe the sportsman who was the most popular in France. A monument of a sportsman and a man is no longer with us. I've been hit very hard."