Katy Perry, who voices Smurfette in this film and The Smurfs 2 (2013), wasn't allowed to watch the original The Smurfs (1981) series as a child. Her parents were highly conservative pastors, and didn't consider it to be good for their children.
The filmmakers cast Katy Perry without knowing it was her: "They had done a blind test where they took certain voices from previous interviews and matched them with the character. They liked my voice without even knowing who it was, and when they found out it was me, they thought that would work out. My personality was just a plus!"
During filming, each Smurf was represented by a different colored dot on the set, and actors and actresses had to remember which dot was which Smurf.
268 Sony Pictures Imageworks employees spent around 358,000 hours animating the Smurfs.
According to Belgian cartoonist Peyo (Pierre Culliford), the Smurfs never take off their caps. However, they do so in the movie, by using them as parachutes when jumping down from an apartment balcony. Relatives of Peyo demanded that for that scene, the Smurfs are seen only from above or below.