Leung's father saw an advertisement for a Harry Potter and the Goblet of Fire casting call, and suggested she should try out. She waited four hours in line for a five-minute audition, despite feeling she had little likelihood of obtaining the role. Two weeks later, she was called back for a workshop and was cast as Cho Chang, beating out over 3,000 other girls for the part. In retrospect, she stated in an interview with the Daily Record that her Scottish accent probably gave her an advantage in the casting, as the casting director asked the girls who attended the audition, "Is there anyone here from Scotland?", to which only Leung raised her hand. In a 2011 interview, Leung said her fondest memory of the Harry Potter experience was the first audition, because both her parents, who were separated at the time, went with her. "It was a really nice moment because my parents hadn't seen each other for a long, long time," Leung said. In an effort to heavily promote Harry Potter and the Goblet of Fire, Warner Bros. sent Leung to China in the film's second week of release, which was unusual for a market not used to frequent celebrity visits.