"Never Let Me Go" is Carey Mulligan's favorite novel. She was certain someone would make a film adaptation, and had hoped they could wait until she was old enough to play Kathy. She couldn't bear the idea of anyone else portraying Kathy, although she acknowledged that she thought other people would be able to do a better performance. She actively campaigned for the role.
Mark Romanek said that working with child actors was the most challenging part of making the film, since "the first act of the film was going to have to be carried by 12-year-olds." Durning pre-production, Romanek had the younger actors watch the older actors rehearse the younger scenes, so the older actors would have a memory of having played those scenes, while the child actors would get a better idea of how more skilled actors would play their parts. He also had the child actors spend time together, playing and talking to create chemistry between them. He took them to the school set and let them play there so they could get a better idea of the layout.
Carey Mulligan had to learn how to drive for the film. She took a two-week intensive course, but failed the driving test. Her scene was shot on a private road, where she was allowed to get behind the wheel.
Keira Knightley admitted that she only agreed to appear in the film because her friend and co-star Carey Mulligan had asked her to. She said she was unable to relate to Ruth's involvement in a love triangle.
Alex Garland asked Kazuo Ishiguro for the rights to his novel before he finished reading it.
Andrew Garfield described Tommy as "animalistic and sensory and feeling. There's a sense of anxiety that runs through these kids, especially Tommy, that's my perspective of him."
Mark Romanek found making Keira Knightley look plain almost impossible. He told an interviewer "It was difficult. She was eager and happy to do it because the role called for it. But even at her worst, Keira still looks astonishing".
Kathy proved to be difficult to cast. Peter Rice, head of Fox Searchlight, texted Mark Romanek halfway through a screening of An Education (2009) and said "Hire the genius Mulligan".
Composer Rachel Portman described her score as a "chamber piece." She worked with an orchestra of 48 players, including piano, strings, and harp, plus a violin and cello for solos. She felt that a smaller orchestra was needed for a minimal, more restrained intimate score. Because of the film's sad story she wanted the music to have some hope, humanity, and heartbeat.
Mark Romanek described the film as "a love story with fictional science context mixed in." He considered filming some futuristic elements, but decided it didn't feel right.
The German title, "Alles, was wir geben mussten," translates to "Everything We Had to Give".
Mark Romanek was glad to get the opportunity to direct this film. "From the moment I finished the novel, it became my dream to film it. Kazuo Ishiguro's conception is so daring, so eerie and beautiful."
Kazuo Ishiguro, the author of the source novel, has been awarded a Literature Nobel Prize.
The external shot of Ruth's Care Facility is Andrew Melville Hall, one of the Halls of Residence for students at the University of St. Andrews, in Fife, Scotland.
Mark Romanek had just dropped out of directing The Wolfman when the opportunity to helm Never Let Me Go (2010) came his way.
Some scenes were shot at the beach at Holkham, where Keira Knightley had filmed The Duchess (2008) a few years earlier.
The visit to Norfolk, on England's east coast, was filmed in Clevedon and Weston-super-Mare, on England's west coast.