The annual festival runs 11 days and will screen entries from 34 countries. Films include Sofia Coppola's "Somewhere," "Essential Killing" by Polish director Jerzy Skolimowski, and "Three" by German director Tom Tykwer.
A mystery contender is expected to be announced on Sunday.
Travel ban
Noted Iranian filmmaker Jafar Panahi was unable to attend the festivities after the Iranian government confiscated his passport in retaliation for a film about the aftermath of Iran's disputed 2009 election.
Panahi's critical film "The Circle," about the treatment of women in Iran, won the festival's Golden Lion award in 2000.
US director Quentin Tarantino will head the jury, which includes French filmmaker Arnaud Desplechin, screenwriter, director and producer Guillermo Arriaga of Mexico and Italian director and screenwriter Gabriele Salvatores.
Prizes include the Golden Lion for best film, Volpi Cups for best actor and actress, and a special jury prize.