Bridge where old Eric standing at the end of the movie is the famous Bridge on the River Kwai in Thailand.
The real-life Patti Lomax attended the film's world premiere at the Toronto Film Festival in 2013. She received a standing ovation upon the screening of the film. She also attended 20. Sarajevo Film Festival in Bosnia and received a standing ovation.
The film uses compressed time to speed up the story. Eric Lomax and Patti Lomax did meet in 1980, but in reality they didn't marry until 1983. Eric didn't learn that Takashi Nagase was still alive until 1993, and they finally met in 1995.
Jeremy Irvine was cast as the younger version of Colin Firth's character, after Firth himself suggested him for the role.
Rachel Weisz was originally cast as Patti Lomax, but was forced to drop out due to scheduling conflicts, with re-shoots planned for The Bourne Legacy (2012) and Oz the Great and Powerful (2013). Nicole Kidman replaced her after being asked to take the part by Colin Firth himself.