Writer Brian Helgeland first saw the original Man on Fire (1987) when he was renting videos in the late '80s. He walked in to the video store where Quentin Tarantino was working and asked what was good. Tarantino recommended "Man on Fire".
Denzel Washington was so impressed with Dakota Fanning's acting that he'd watch her and forget he was in the scene.
The kitchen scene between Creasy and Pita, where she asked him about concubines, was mostly ad-libbed. It started when they "accused" each other of smiling.
Denzel Washington was cast because of a trip to a doctor. He ran into director Tony Scott in the waiting room of a medical office and the two started chatting. Scott had not seen Washington in person since they worked together on Crimson Tide (1995). Scott happened to see Dakota Fanning in I Am Sam (2001) the night before and seeing him made Scott think of using them together.