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!"
The filmmakers made the decision (after numerous tests) to depict the Smurfs at 7½ inches: any larger, they would no longer appear as the lovable creatures as they are known for; any smaller, it would be difficult for them to relate to real-world objects and people.
This is the third blue-skinned character Alan Cumming has portrayed. The first was the mutant Kurt Wagner also known as Nightcrawler in X2 (2003), and the second was the Judas Caretaker from Riverworld (2010).
According to Peyo, 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.
Hank Azaria is the third actor to play Gargamel. Paul Winchell voiced Gargamel until the last cartoon season (1989-1990), and an unknown voice actor took his place after Winchell allegedly walked out of his role due to issues with the Season 9 script.
The town of Júzcar (Malaga, Spain), one of the "White Towns of Andalusia", was chosen by Sony as the place of worldwide release for "The Smurfs". For the occasion, all the white houses and buildings were painted blue. The local citizens decided in a referendum to keep the color until the end of summer 2011.
Producer Jordan Kerner had been wanting to make a film adaptation of The Smurfs since 1997, and obtained the rights in 2002, after Peyo's heirs were impressed with a draft of Kerner's adaptation Charlotte's Web (2006).
Jordan Kerner was Dean of the School of Filmmaking at the University of North Carolina School of the Arts (UNCSA). Nearly 80 UNCSA film students interned on the film during its various stages of production.
The film was initially set up at Paramount Pictures and Nickelodeon Movies, were it was planned as a fully animated film, which would have been the first of a trilogy. The project switched to Columbia Pictures and Sony Pictures Animation in June 2008.
For the first time in Smurfs history, Brainy Smurf is depicted with freckles. He is not, however, the first Smurf with freckles as the comic version of Sassette has freckles. The cartoon version (which she made her debut) did not.
Contrary to popular belief, the phrase that is often described the height of most Smurfs ("haut comme trois pommes", a French idiom which directly translated reads "three apples high") was never a precise scientific measurement. It means that something is really small, and an English equivalent would be "knee-high to a grasshopper".
Anton Yelchin, who voices Clumsy Smurf, described his role as a little sweeter than in the original cartoon: "Clumsy isn't trying to mess anything up for anybody - he's just clumsy, and actually, he's tired of being clumsy."
The Smurfs originally started out as a comic book, by Peyo. In homage of this, a "Smurfs" comic book plays a pivotal role in the film. The book that the Smurfs find at Mr. Wong's Magical Emporium, "L'Histoire des Schtroumpfs," includes artwork by Peyo from his stories, "The Smurf's Apprentice", "The Fake Smurf", and "The Hundredth Smurf."
The depictions of Farmer Smurf (green overalls and straw hat) and Handy Smurf (blue overalls and a red pencil held on one of his ears) in this film are based on their comic versions since the 1990s. However, unlike the comic depiction, Farmer does not wear wooden shoes (called clogs) but green trousers that cover his feet.
Gutsy, Smurfette and Gargamel are all linked to another movie personage which their character resembles. Gutsy, the Scottish Smurf, yells "Freedom!" like William Wallace does in Braveheart (1995) , also Scottish. When Smurfette shows the other Smurfs her new dress it is blown upwards like Marilyn Monroe's in The Seven Year Itch (1955) while Smurfette tries to hold it down. Gargamel, being a wizard, is linked to the character Gandalf from The Lord of the Rings: The Fellowship of the Ring (2001) as he spots a moth and asks it to bring him eagles to rescue him like the way Gandalf escapes his imprisonment from Saruman.
One of the co-producers of this film is Véronique Culliford, the daughter of Peyo. She is the president and founder of I.M.P.S (International Merchandising, Promotion & Services) which is responsible for the licensing and promotion of Smurfs intellectual property.
There is a Smurf named Panicky that was supposed to appear in the film and was even give a voice actor (Adam Wylie), but he was only mentioned by Gutsy in dialogue. However, he does appear in merchandise sold by fast-food chain McDonald's.
Katy Perry, who voices Smurfette in this film, wasn't allowed to watch the original Smurfs (1981) series as a child. Her parents were highly conservative pastors and didn't consider it to be good for their children.