The lead actor Robert Gustafsson estimated that he had spent a full three weeks non-stop in makeup after principal photography had wrapped. Some days, makeup had to start applying prosthetics at 2 a.m.
The song the nursing home staff sings while bringing Allan his cake is a traditional Swedish birthday song, "Ja må du leva," the lyrics of which translate in English to "May you live, may you live, may you live one hundred years! Of course you'll live, of course you'll live, of course you'll live one hundred years!" (Not included is the cheeky final verse, which states "And after you've lived one hundred years, you'll be taken away in a wheelbarrow.")
Actor Robert Gustafsson was 48 at the time the movie was released, 52 years younger than the character he played.
The Wilhelm scream can be heard when Allan arrives at the Soviet gulag, as a guard shoots a prisoner.
Original literary work:
- "Hundraåringen som klev ut genom fönstret och försvann", novel by Jonas Jonasson, Piratförlaget Publishing, Stockholm, 2009, 394 p., ISBN: 978-91-64202-96-3.