Affleck, who starred in and directed the film, along with George Clooney and Grant Heslov, also received the Darryl F. Zanuck Award for producing "Argo" at the Saturday award ceremony, The Hollywood Reporter said.
Affleck called the wins "incredible, exciting."
"Argo" has already won won two Golden Globes -- best drama and for Affleck's direction -- and has been nominated for seven Oscars, including best picture.
In other categories at the Producers Guild Awards, Disney's Wreck-It Ralph, produced by Clark Spencer, took the animation prize and Sony Pictures Classics' Searching for Sugar Man, produced by Malik Bendjelloul and Simon Chinn, won the best documentary award.
Costly malfunction causes beer flood at Boston-area brewery
Megyn Kelly: Santa Claus and Jesus are both white men