Ricky Jay, the narrator, is an actor who has appeared in films for such filmmakers as Paul Thomas Anderson and David Mamet, but he is perhaps better known as an expert on the histories of magic, "spirit" photography, and con artistry, and as such is a logical choice to narrate a film about con artists. Rian Johnson had originally asked Jay to play The Curator, but Jay's schedule didn't allow for that, so Johnson hired Robbie Coltrane for that role instead.
Tom Cruise is credited with special thanks in regards to the film, due to his initial interest in the film, that led to a lengthy three hour meeting with Rian Johnson. Cruise's analysis of the script led to a few significant changes of the key elements of the script. As this meeting occurred precisely the same day Cruise's company was taken off by Paramount, Rian felt this was a more than generous act on Cruise's behalf. However, due to scheduling conflicts, as well as other factors, Cruise could never be a serious consideration for one of the lead roles.
Penelope's quote, "A picture is a secret about a secret. The more it tells, the less you know" is actually a quote by acclaimed American photographer Diane Arbus (1923-1971). The biographical film Fur: An Imaginary Portrait of Diane Arbus (2006), featured Nicole Kidman as Arbus, one of the twentieth century's most revered photographers. Incidentally, "arbus" is Russian for "watermelon", which might explain why one gets turned into a camera by the Penelope character.
The three main characters are based on characters from James Joyce's "Ulysses" (which in turn is based on Homer's "Odyssey"). Stephen is based on Stephen Daedalus, a restless young writer in two of Joyce's novels; in "The Brothers Bloom", Stephen plans their cons with a writer's flair. Bloom is based on Leopold Bloom, who is wandering around Dublin, trying to find himself and his way back to his wife. In The Brothers Bloom, Bloom is figuratively looking for himself, and ultimately finds his way to Penelope. In "The Odyssey", Penelope is Odysseus' wife who waits for him through all of his travels; likewise, here, Penelope awaits Bloom through his wanderings.
Early in the film a character says, "The man named Charleston you met nine months and a thousand years ago at the hotel bar in Jodhpur is dead." to which Stephen later says "That's Kipling, isn't it? He stole that from Kipling." This is in reference to Rudyard Kipling's "The Man who Would Be King". In the film adaptation (The Man Who Would Be King (1975)), there is a line spoken by Michael Caine, saying he is "The same and not the same - who sat beside you in the first class carriage on the train to Marwar Junction; three summers and a thousand years ago...", but the line does not appear in the original short story.
Penelope's house in New Jersey, is actually the Peles castle, located in Sinaia, Romania. Also, the building near the sea, where Bloom is going to meet the kidnappers, is the Casino of Constanta, Romania.
The bar scene towards the beginning of the film is Rian Johnson's homage to his own film, Brick (2005). It features four cameos from the cast of that film, however, only two are credited: Norah Zehetner as "Rose", and Noah Segan as "The Duke". The faces of Joseph Gordon-Levitt and Lukas Haas can be seen in a panning shot of the crowd. Levitt played the lead "Brendan" in "Brick", Zehetner played "Laura", Haas "The Pin", and Segan "Dode".
Out of the quartet of caperers, Rian Johnson found the character of Bang Bang the most fun to write. Bloom was the easiest, and Penelope was the most difficult, because he wanted her character to transcend the sum of her quirks, despite having the most personal connection to her. Johnson has also admitted to wishing he could be Stephen.
Seen only for a second, here are the fifteen steps as laid out by the Bloom brothers as young boys for their first con: 1. Bloom talks to girl. 2. Bloom wins kids trust. 3. Stephen finds a cave. 4. Stephen loosens dirt in cave. 5. Stephen buys supplies. 6. Cut percent O'Henrys. 7. Bloom further endears self. 8. Stephen scouts church. 9. Stephen procures non-slip boots. 10. Bloom comes home to find Stephen filling coolers. 11. Bloom pitches the tale. 12. Bloom leads kids to cave. 13. Mud mud mud! 14. Bloom/Stephen busted. 15. O'Henrys Pay off! rocket pops.