Continuity mistake: At Edward Nygma's party at the Ritz Gotham there is a fountain with a large version of his "box" on top. When Two-Face comes, he shoots the "box" and destroys it. There should be some parts left over but when Batman falls through the ceiling he lands on the fountain and there's no remains of the "box." (01:12:15 - 01:13:30)
Continuity mistake: When Chris O'Donnell does the laundry and is putting wet clothes on the string, he takes a clothing item and wraps it around his right leg then twists water out of it. When he does this his right foot goes in the air a few inches above the ground but in a closeup to his foot and water falling it is his right foot standing when it should be his left. (00:55:00)
Continuity mistake: In the scene at the circus when the ringmaster announces "The Flying Graysons", Robin's mom is standing on his left side. In the very next shot, she is on his right side. Also, when Robin is doing the "Death Drop", his mom is on his left and his brother is on his right side. After he completes the stunt and he swings back up with his dad, his mom and brother have switched places. (00:32:45)
Continuity mistake: When checking a tape that shows the (fake) suicide of Stickley, Bruce is handed the suicide letter, which was folded in three parts. The next shot shows a clean sheet of paper, with no wrinkles or folds. (00:26:20)
Continuity mistake: When Riddler and Two Face are stealing diamonds, the Riddler is holding a large diamond. Two Face comes over to him and produces an even bigger one. However, if you look closely at the shots, the diamond the Riddler holds gets smaller in one cut, and Two Face then pulls out the diamond Riddler was just holding...
Continuity mistake: In the scene in which Edward is first testing his "box", watch Ed's left shoulder. He goes to turn off the machine, then says his line "What a rush." The shot cuts to Ed's boss briefly. When the shot cuts back to Ed, his left shoulder strap, which was present in every other shot, is missing. He even reaches to take the strap off as he starts to say "A very surprising side effect." Apparently, he didn't even notice that it had fallen off.
Continuity mistake: When Bruce is reading the riddle about vowels, it starts out "We're five little items of an everyday sort." He pushes the button to read the second part of the riddle. Then when Bruce walks around, the first part of the riddle can be seen again. (01:33:25)
Continuity mistake: When Batman jumps up into the Riddler's lair, he's gone up the outside of the shaft - we see a shot from his point of view right up to the point of entry, and he's right at the edge. But when he jumps back into the shaft, despite not having moved, he's suddenly right in the middle of it.
Continuity mistake: While retrieving the safe from the chopper, Batman tells the bank guard to "hang on." The guard holds on to the chain to which the safe is attached. But as the safe comes back into the vault, the bank guard is holding on to one of the tubular structures of the safe itself. (00:09:35)
Continuity mistake: After causing Two-Face to accidentally blow up a car that had a couple members of his gang in it, with his missile-launcher, Batman speeds by Two-Face with the Batmobile as he is being chased by other members of Two-Face's gang. In one shot the Batmobile is very close to Two-Face, but in the next shot the Batmobile is far away from Two-Face (when he tries to throw his missile-launcher at the Batmobile). (00:49:05)
Continuity mistake: When Bruce is at Dr. Meridians place, Bruce receives a call from Alfred. Bruce moves his finger on the side of the communication device up. The next shot shows him doing it again. (01:02:05)
Continuity mistake: In the fight scene outside the elevator at the beginning of the movie, there are at least two shots where you see Batman's back without his cape in the way. There are no items whatsoever attached to the back of his belt. Subsequently he manages to pull the stun device and the grappling gun with grappling hook from behind his costume. A previous corrector proposed that the devices could not be seen because they are concealed in "pouches" on Batman's belt. Close inspection of the scene shows that there are no pouches of any kind on his back or concealed in his cape.