In an interview with AFP ahead of the Friday US release of "The Great Beauty," he told how its setting in Rome gave him a particular challenge - forgetting how masters such as Fellini captured the Eternal City before him.
The film, premiered in Cannes earlier this year, is Italy's candidate for foreign film Academy Award, in a long list that will be slashed down to five nominees on January 16th, when all the nominations are announced.
"The Great Beauty" evokes the decline of one side of Italy through the eyes of a cynical journalist played by Sorrentino's favorite actor Toni Servillo.
The director is returning to his homeland after a detour to the US for 2011's "This Must Be The Place" (2011) with Sean Penn.
Sorrentino, from Napoli, said the Italian capital was the obvious choice to set his latest project - but acknowledged the shadow of all the greats led by Fellini who have brought Rome to the big screen.
"I tried to imagine that it's the first film shot in this city and in these surroundings, about these people," he told AFP.
"Being a film buff can be dangerous: if you spend too long thinking about films that have already been made, it can paralyze you, because you constantly have these references in your head.
"So it's very important to make oneself believe that it's the one and only time that this has been done. Therefore I had to avoid watching other films or other ways in which the city has been presented."
The music which provides the film's soundtrack also evokes the city's "duality," mixing pop songs with madrigals.
"Rome is a city which has an enormous capacity to have the sacred and the profane side by side, and I had the same philosophy for the music. I tried to mix the two, and to see how they could work together," he said.
Among the most powerful scenes are orgiastic parties which the cynical journalist, Jep Gambardella, holds on his terrace overlooking the Colosseum.
"It was something new for me, as I had never filmed parties .. I really liked shooting it because I love watching people dancing. It's one of the things I want to see in a film, as a director."