Trivia: Michael Keaton had to wear a separate cowl with shorter ears for the scenes where he gets in and out of the Batmobile. The vehicle's sliding canopy feature had been designed based on his pre-costume measurements, and it was only once filming had started that the crew realised they hadn't thought to measure him again while in the batsuit, so they could account for how much extra height the ears added.
Trivia: The Batmobile went through the full process of being designed, drawn up, signed off on, and built at full scale, before someone thought to ask "Wait, where's the door?" Since the designs called for giant intake vents where the doors were supposed to be, nobody had thought about how Batman was supposed to get in and out of his vehicle. The team quickly came up with the alternate idea of having the Batmobile's canopy slide open like a jet fighter so he could climb in.
Trivia: When the film was announced, a lot of people thought that Michael Keaton was a poor choice for the role of Batman, because in the 1980s, he was only known for his comedic roles. Batman fans were so against the casting choice the 50,000 protest letters were sent to the Warner Brothers offices. Even Bob Kane, who created Batman, felt that Keaton was a bad choice.
Trivia: In order to make the bat boots, Nike air 3 trainers were used.
Trivia: Before the film was released, fans paid for a ticket at theaters just to see the trailer and leave.