The newspapers seen in the movie were printed on the presses of The Washington Post.
Director Kevin Macdonald intended the movie to pay homage to All the President's Men (1976) by using the Watergate Hotel and the parking garage as locations.
Brad Pitt and Edward Norton originally signed on for this movie that would have reunited them for the first time since Fight Club (1999). However, Pitt pulled out before Thanksgiving 2007, when re-writes were made impossible because of the writers' strike. He was replaced by Russell Crowe. Pitt's departure delayed the start of shooting, and made Norton unavailable, as he was committed to start shooting Leaves of Grass (2009) in January. He was replaced by Ben Affleck.
There is a partially hidden photo of real-life Washington Post reporters Bob Woodward and Carl Bernstein of 1970's Watergate fame on the wall of McAffrey's cubicle.
The scene in which Cal (Russell Crowe) orders lunch, but is then interrupted by his bag getting stolen, was shot at Ben's Chili Bowl, a real Washington, D.C. lunch counter that has been open on U Street NW since 1958.