Juergens, who came from Austria but also held Swiss nationality, took ill while walking in the countryside in northeastern Switzerland, his management team said in a statement.
He was taken to hospital in the town of Muensterlingen but died there.
Juergens had composed more than 1,000 songs and sold more than 100 million records.
He won the Eurovision song contest in 1966 with "Merci cherie" which was a hit in several languages, including French, English, Dutch and Italian.
Member comments