Filmed in Rome and Tuscany last summer, the hotly anticipated Italian-language feature – titled Loro or "Them" – does not yet have an official release date, but is expected to premier at the Cannes Film Festival in May.
Sorrentino, best known internationally for his Oscar-winning film La Grande Bellezza (The Great Beauty) and the TV series The Young Pope, has said he wanted to profile Italy's most infamous living politician because "he is an archetype of Italianness and through him, you can describe Italians".
To judge by the trailer released on Monday, the film will focus at least as much on Berlusconi's personal life as his long career in media and politics.
"I was interested in the man that’s behind the politics, but I am not so interested in the political stuff," Sorrentino told the BBC last year, explaining that he would also tell the story of those around the businessman-turned-politician who tried to use his position to "change the course of their own life".
The teaser features multiple women, many of them scantily clad, but only a passing glimpse of Berlusconi, played by Toni Servillo.
Paolo Sorrentino (L) and Toni Servillo with the 2014 Academy Award for Best Foreign Language Film for La Grande Bellezza. Photo: Kevork Djansezian/Getty Images/AFP
The Neapolitan actor – who starred in La Grande Bellezza as well as Il Divo, Sorrentino's musical biopic of another former premier, Giulio Andreotti – has already impressed the Italian media with what La Repubblica called his "metamorphosis". Photos from the set showed Servillo sporting Berlusconi's trademark tan and distinctive hairline; now he's winning praise for his spot-on impression of the four-time prime minister's voice.
We've only heard him say one line so far. Loro's trailer opens with a man's voice asking, "What did you expect: to be the richest man in the country, become prime minister and be madly loved by everyone too?"
As Berlusconi, Servillo replies: "Yes, that's exactly what I expected."
It's not clear if the real Berlusconi has seen the film. While he originally offered to allow Sorrentino to shoot inside his private villas, by October last year he said he had heard unwelcome rumours that the film might be a "political aggression towards me".
According to La Repubblica, Sorrentino did get the chance to meet Berlusconi's second ex-wife, Veronica Lario, with whom the politician is engaged in a long-running legal battle over alimony. Played by Elena Sofia Ricci, Lario also features in the trailer, looking mournful on a trampoline.
Berlusconi's pet poodle Dudù also makes an appearance.
The teaser comes just a week after Berlusconi's greatest political defeat to date: his Forza Italia party won just 14 percent of the vote in Italy's general election, making it second within the centre-right bloc to the populist League. Should the group manage to form a government, the League – not Berlusconi – now gets to decide who will be prime minister.
Little has been seen or heard from Berlusconi publicly since the results came in. Many expect it to be the last time that the 81-year-old leads his party into an election, despite his supposed political immortality.
"The world has an idea of Berlusconi [as] a very simple person," Sorrentino told the BBC. "But... I understood that he is more and more complicated than this. I would love to try to describe this complex character."