Pacino's films include Heat, Donnie Brasko and The Godfather

"It means so many things to be honoured like this," the Godfather star, 67, said at a gala reception in Hollywood's Kodak Theatre. "It feels great".

Later, he joked: "Seeing my life in the movies, I have one question, and that is: Why aren't I in rehab?"

A host of Hollywood heavyweights, such as Oliver Stone and Andy Garcia paid tribute to Pacino at the reception.

"The depth of your artistry is only more overwhelmed by the generosity of your spirit and your warmth," said Garcia, who worked with Pacino on The Godfather: Part III and Oceans 13.

Kirk Douglas was one of the actors to pay tribute to the star

"You're Van Gogh. You're Modigliani. That's who you are."

Stone, who wrote 1983's Scarface, lauded the actor's "wicked sense of humour".

"It is with great love and respect that I say goodnight to the bad guy," he said, recalling one of Pacino's famous lines from the gangster movie.

Family pride

Pacino's sister, Roberta, also spoke of her brother's love of performing.

"He's one of the greatest artists who ever lived, according to me," she said.

The actor is still best known for playing Michael Corleone in the Godfather movies, but he won the best actor Oscar for Scent Of A Woman in 1993.

Pacino's co-stars Andy Garcia (l) and Chris O'Donnell (r) attended

In the same year, he was also nominated for best supporting actor for his role in Glengarry Glen Ross.

But before his film career took off in the 1970s, Pacino's first love was the theatre - which was where actor Kirk Douglas first laid eyes on him.

"Forty-five years ago I was in a theatre and I thought, 'Who is that guy?'" recalled the 91-year-old.

"I look at my little program and it said Al Pacino.

"I said to him, 'You're going to be a star.' But I didn't expect 45 years later to be here."

Dali film

Picking up his prize, Pacino recalled that he discovered acting while growing up in New York.

"By age three, I was doing Al Jolson," he said. "I found, in the theatre, this place I could go to. I found this peace."

Gabrielle Anwar and Jamie Foxx took part in the three-hour gala

The actor also said he was looking forward to taking on new projects, including a celluloid reunion with Robert De Niro, and a biopic of Salvador Dali.

Previous recipients of the AFI lifetime achievement award, now in its 35th year, include Sir Sean Connery, Martin Scorcese, Dame Elizabeth Taylor and Steven Spielberg.

Pacino has won numerous acting accolades during his career, which spans over 40 years.

He has been nominated for an Academy Award eight times and was also the recipient of the Golden Globes' prestigious Cecil B DeMille career achievement award in 2001.

His other films include Donnie Brasko, Carlito's Way, Dog Day Afternoon and Heat.