Shared with you
Mathilda wants Norman Stansfield dead in order to avenge the death of her brother, which was the only member of her family that she cared about. Although Stansfield kills the rest of Mathilda's family, her brother is actually killed by Stansfield's henchman Willi (you can hear Malky scolding him for it when Mathilda walks by the entrance to the apartment, right after the raid). This means that she is actually present to witness the death of her brother's killer, as she is in the room when Léon shoots him.
According to Jean Reno, he decided to play Léon as if he were "a little mentally slow" and emotionally repressed. He felt that this would make audiences relax and realize that he wasn't someone who would take advantage of a vulnerable young girl. Reno claims that for Léon, the possibility of a physical relationship with Mathilda is not even conceivable, and as such, during the scenes when such a relationship is discussed, Reno very much allowed Portman to be emotionally in control of the scenes.
This is Natalie Portman's motion picture debut. Born in 1981, she was 11 years old when she was cast.
When the film was first tested in Los Angeles, California, USA, the version that was screened included a short scene where Mathilda asks Léon to be her lover. However, the audience became extremely uncomfortable and began to laugh nervously, completely destroying the tone of the film. The film received terrible test scores at the screening, and as such, producer Patrice Ledoux and writer/director Luc Besson decided to cut the scene for theatrical release.
Keith A. Glascoe, who played the enormous Benny, or 3rd Stansfield Man, later became a member of the New York Fire Department, Ladder Company 21 in Hells Kitchen. Courageously, he died in the collapse of the World Trade Center towers on Sept. 11, 2001.
Luc Besson: In the "International Cut", he is the guy shooting back at Léon and Mathilda, who Léon kills by using the grenade "ring trick".