Trivia

His wife Minnie is a great-granddaughter of Henry Morgan Tilford, a founder of the Standard Oil Company (portrayed as "H.M. Tilford" in Petróleo sangriento (2007).

Has written two screenplays where Harrison Ford was offered a role: Robert Wakefield in Tráfico (2000) (which went to Michael Douglas) and Bob Barnes in Syriana (2005) (which George Clooney won the Oscar).

Turned down the offer to adapt "El código Da Vinci (2006)".

He has a son and a daughter from his relationship with actress Michael McCraine.

Has directed one Oscar-winning performance: George Clooney in Syriana (2005).

Turned down an offer to write the script for Indiana Jones y el reino de la calavera de cristal (2008).

According to the 2000 Film Writers Directory, Gaghan had worked on a early draft of Last Resort (1994).

He had attempted to get a staff writing job on Saturday Night Live (1975).

He had written a 80 page spec script for Los Simpson (1989) entitled "Family Wheel of Jeopardy", that was read by show producer Sam Simon, who wanted to hire him, according to Gaghan this didn't happen due to Simon leaving the show, and Simon's replacement, David Mirkin, reportedly saying that Gaghan's script wasn't "Simpsonsesque".

He had attempted to get a staff writing job on Baywatch Nights (1995), but was rejected.

He had written an unproduced screenplay titled "The Underachievers", a story about some people who try to start a catalog company in Chicago.

He had written a spec script for Seinfeld (1989).

Early in his career, he had pitched an idea for Red Shoe Diaries (1992) that was rejected.

He had started a catalog company called "Fallen Empire".