Clooney and Pitt were on the red carpet for the premiere
The Venice Film Festival has opened with the premiere of the Coen brothers' dark comedy Burn After Reading.
The film, starring George Clooney and Brad Pitt, is showing out of the competition at the annual event.
Before the screening, the stars posed good-naturedly for pictures and signed autograph books for fans lining up along the red carpet.
There are 21 movies competing for the coveted Golden Lion this year, with entries from Ethiopia and Turkey.
The festival continues with a fly-on -the-wall film about fashion designer Valentino Garavani - billed as a glimpse into a world of bygone glamour.
The movie was directed and produced by special correspondent for Vanity Fair magazine, Matt Tyrnauer.
Pitt and Clooney are joined by British actress Tilda Swinton in Ethan and Joel Coen's latest offering.
Clooney plays a paranoid federal marshal who gets mixed up in a conspiracy involving a former CIA analyst's missing memoirs.
Also involved are the analyst's adulterous wife, played by Swinton, and a couple of gormless gym instructors played by Pitt and Frances McDormand.
Before the premiere, Pitt picked up an award that he won in Venice last year - the best actor's prize for The Assassination of Jesse James by the Coward Robert Ford.
"You can run but you can't hide," Pitt joked as he accepted the award.
"It was an honour to receive this last year and it remains an honour to accept this this year."
Among the favourites for the Golden Lion are Japanese directors Takeshi Kitano, with Achilles and the Tortoise, and Hayao Miyasaki, for the animated feature Ponyo on the Cliff by the Sea.
The prize will be awarded on 6 September.
Other strong contenders include US director Darren Aronofsky's The Wrestler, starring Mickey Rourke, and French film-maker Barbet Schroeder's thriller L'Inju: la Bete dans l'Ombre, or The Beast in the Shadows.