When R (Nicholas Hoult) is talking to Julie (Teresa Palmer) outside her house, the scene is referencing the balcony scene of "Romeo and Juliet." R (Romeo) is talking to Julie (Juliet) on the balcony.
In the book, R wears a black suit with a red tie -identifying him as a corporate "zombie" - and has a zombie wife and zombie kids he has to feed. The film ditches all of this to age the character down and dresses him in jeans and a hoodie.
When Julie (Teresa Palmer) leaves the airplane for the first time on her own, one of the first zombies in the small group on the tarmac looks like Rick (Andrew Lincoln) from the TV show The Walking Dead (2010).
When R (Nicholas Hoult) returns to the airport with Julie (Teresa Palmer) for the first time after the raid at the lab, an automated announcement in the background can be heard, saying, "The white zone is for loading and unloading of passengers only." This is taken from Airplane! (1980) at the beginning of the movie, when Ted first arrives at the airport.
In R (Nicholas Hoult)'s home (the abandoned airplane), it turns out he owns a Blu-ray of the movie Zombie (1979)) directed by Lucio Fulci, often noted as being one of the greatest zombie movies of all time.
In preparation for their roles as zombies, the cast and extras went through "zombie camp" where they learned how to move and react as walking corpses.
The image on the movie poster of R giving Julie flowers never occurs in the movie, but did occur in the book.
Teresa Palmer mentioned on the DVD commentary that one of the moves she does during the zombie fight with the weed whacker, is an homage to one of her previous roles, Number Six in "I am Number Four"
The character Nora was originally described as having brown skin and being half Ethiopian, but they instead decided to go with a Caucasian actress (Lio Tipton).
Teresa Palmer mentions in the DVD commentary that her first day of shooting was when she was kissing Perry (Dave Franco) in the car and confessing her love to him (and the camera as it is from Perry's perspective.
Two of Dave Francos movies, 21 Jump Street (2012) and Warm Bodies (2013), feature the same two songs on their respective soundtracks, which are John Waite's "Missing You" and "Midnight City" by M83.
The song played at the end of the movie, Runaway, is written and performed by the band The National for their album High Violet. On the album, it is followed by the song Conversation 16 in which the chorus repeats the the line "I was afraid, I'd eat your brains".