Working title: They Came From Upstairs. This title appeared in some early promotional materials before being changed to Aliens in the Attic (2009).

At 17:10, Sparks, the first alien Tom and Jake encounter while on top of the roof, tells them "Hello, humans. We come from upstairs." This line was probably intended as a joke, where the word "upstairs" is mistakenly used to mean "space". It is also the likely source of the working title "They Came From Upstairs".

Malese Jow and Carter Jenkins previously worked together on the Nickelodeon show Unfabulous.

The fourth 20th Century Fox's live-action/computer-animated hybrid film, after Garfield (2004), Garfield 2 (2006) and Alvin and the Chipmunks (2007).

The fourth 20th Century Fox's live-action/animated hybrid film to be rated PG by the MPAA, after Garfield (2004), Garfield 2 (2006) and Alvin and the Chipmunks (2007).