With 4,366 locations, this film also holds the record for opening in the most venues on its release date. (Pirates of the Caribbean: At World's End (2007) opened in 4,362 movie houses the previous summer.)
After seeing his performance in Thank You for Smoking (2005), Christopher Nolan thought that Aaron Eckhart would be perfect for the role of District Attorney Harvey Dent.
The IMAX cameras used in filming proved to be problematic for the crew. Dialog that was recorded on film is very noisy so it had to be replaced during post-production. An IMAX camera is very heavy and it cannot be used hand held. Instead, special mounts had to be created to support the weight. Finally, they had to get the shots right as it takes 5 days to process the negative instead of the conventional negative.
In the part where all the crime leaders are having the meeting with Lou live on TV, the TV screen gives off a green reflection on the table which means that they put a green sheet over the TV screen so that can put over another version (special effects) of the live video of Lou.
The length of The Joker's hair changes throughout the course of the movie on several occasions. It begins mid length then changes to long, then back to short. This is suitable for this chameleon-like, disguise-loving character.
After The Joker tells the citizens of Gotham that he wants Mr. Reese dead in an hour or he will blow up a hospital, Bruce leaves to go to his Lamborghini. While Bruce crosses the room saying "I need you plugged in checking Gordon's men and their families," the TV in the background goes from showing a news broadcast to instantly being off as Bruce passes in front of it.