Paul Bettany was cast as Swede, Jennifer Connelly as his wife and Evan Rachel Wood as their daughter. All dropped out in 2004, after the movie spent many years in development. After 10 years, Connelly returned in the lead role, alongside Ewan McGregor.
Jennifer Connelly told The Times in Oct. 2016: "...there's a scene where I'm naked and dancing around freely in a state by myself..." She had to wear an "embarrassing" hairpiece while shooting the scene to mimic a more bouffant style of pubic hair to fit the film's 1960s setting. She added that she finds on-screen nudity difficult. Even though she has performed nude in previous films, she admitted "I felt exposed in a lot of ways. I have never done anything like it before. After they shouted cut, I just hid in my trailer."
Ewan McGregor insisted on rehearsals and clearing the set for the actors to become familiar with each other and their characters so they could comfortably work together before shooting any scenes.
During the shoot Ewan McGregor would hone his New Jersey accent by listening to recordings of Ray Liotta dialog while on location.