Will Smith didn't believe it was really Steven Spielberg on the other end of the line when the executive producer first called to talk to him about Men in Black (1997).
Tommy Lee Jones only accepted the role of Kay after Steven Spielberg promised the script would improve. He had been disappointed with the first draft, which he felt did not capture the tone of the comic.
The site BadAstronomy, famed for bashing science fiction movies (such as Armageddon (1998)) about their science blunders, praised this movie for being comedic, yet surprisingly accurate, when it comes to astronomy facts.
Will Smith, after reading the script, did not want to accept the role because one year before he had starred in Independence Day : Le Jour de la riposte (1996) and he didn't want to make another movie about aliens. His wife Jada Pinkett Smith convinced him to take the part.
During pre-production, Barry Sonnenfeld changed a lot of the film's aesthetic: "I started out saying aliens shouldn't be what humans perceive them to be. Why do they need eyes? So Rick did these great designs, and I'd say, 'That's great - but how do we know where he's looking?' I ended up where everyone else did, only I took three months."