During production, Brian Helgeland was brought in to rewrite the script. The Wachowskis, unsatisfied with the rewrites, petitioned to have their names removed from the credits, but were denied this request by the WGA.
When Miguel Bain is arrested by the police after the cemetery shoot-out and being driven in the back of a police car, as the cops are inspecting his weapons he says "Cuidado con las armas, que las carga el diablo". This roughly translates to: "Be careful with the guns, they are loaded by the devil".
Electra's cat seen in the film is a Maine Coon. The same cat appears in the film The Specialist (1994), also starring Sylvester Stallone.
Richard Donner claims the film would have worked better if he swapped Sylvester Stallone and Antonio Banderas.
Richard Donner: [Political Statements] The buses all have anti NRA signs on them: Electra is spraying a coat made out of fur with red paint, a big sign on the front door of the pet shop writes "We won't sell pets - Please adopt one", a female customer in the café is wearing a Pro-choice T-shirt.