Marilyn's line, "Dismiss your vows, your feigned tears, your flattery / for where a heart is hard they make no battery" is from Shakespeare's poem, Venus and Adonis.
Miles's line, "Whoever loved that loved not at first sight" is from Christopher Marlowe's poem "Hero and Leander".
Miles's line "The fault, dear Brutus, is not in our stars but in ourselves" is from Shakespeare's play Julius Caesar.
The Coen Brothers stated that the film was nearly in the works for eight years. It initially began as a project they wrote up for Universal.
Director Trademark: [Joel Coen] [Kubrick] The "beeping" sound effects of Herb's medical equipment are taken directly from 2001: A Space Odyssey (1968), specifically the radar sound effects of the Jupiter pods.
The book that Marilyn is reading is "Into Thin Air" by Jon Krakauer, a book about climbing Mount Everest.
When Weezy Joe shoots himself, the glass behind him has a hole in the shape of a heart where the bullet went through.
Massey's ancient superior, Herb Meyerson, is aided by several medical life support machines, one of which makes the same sound as the tracking radar in the rescue pod from Stanley Kubrick's 2001: A Space Odyssey (1968). When Massey and Meyerson shake hands, the pod radar's 'lock-on' sound can be heard.
In this film, George Clooney plays a talkative character who is vain about his teeth. In his previous Coen Brothers film, O Brother, Where Art Thou? (2000), he plays a talkative character who is vain about his hair.
The slogan on the sign at the N.O.M.A.N. convention (behind the speaker's podium) is "Let N.O.M.A.N. put asunder..."
Catherine Zeta-Jones was pregnant of her daughter Carys during the shooting of the movie, which was filmed immediately after Chicago (2002), Zeta-Jones' Oscar vehicle.