"There is serious urban degradation, an overuse of the city, an insufficient attention to the artistic heritage of the city," the angry prince, Ottaviano de Medici, said in a statement.
The prince said he had presented a project called "Save Florence" on the website www.de-medici.com with 16 proposals sent to Florence city authorities and Italy's Unesco representation.
The Medici heir said the problem was that the 16 million tourists who visit Florence every year only spend an average of two days - and some as little as just a few hours - there as tour operators organize trips around just the main monuments.
Since the landmarks are concentrated in a small space, he said tourists damage the city centre's small paved streets and the monuments themselves, while only stopping to make a few purchases.
"The effects are disastrous," the aristocrat said. "The image of the city has been destroyed by long queues and tourists," he moaned.
He also said he was bothered by "wild nights" of hard-drinking tourists and the "invasion of fast-food joints and shops managed by immigrants."