On November 16, 2007, Summit Entertainment announced that Stewart would play main character Isabella "Bella" Swan in the film Twilight, based on Stephenie Meyer's bestselling vampire romance novel of the same name. Stewart was on the set of Adventureland when director Catherine Hardwicke visited her for an informal screen test, which "captivated" the director. She starred alongside Robert Pattinson, who plays Edward Cullen, her vampire boyfriend. The film began production in February 2008 and finished filming in May 2008.
Twilight was released domestically on November 21, 2008. Stewart's performance garnered mixed reviews with some critics describing her as "the ideal casting choice" and praising her for conveying "Bella's detachment, as well as her need to bust through it;" others criticized her acting for being "wooden" and lacking variety in her facial expressions, which they described as "blank".