Director Barry Sonnenfeld originally didn't want to cast Tommy Lee Jones as Agent K due to the actor's reputation for being a bit difficult to work with. Sonnenfeld once confessed that after seeing Jones give an interview, he told his wife, "Thank God, as long as I live I will never, ever have to work with that jerk." Funnily enough, the two ended up working very well together.
Friends alum David Schwimmer also turned down the role of Agent J due to a film he was directing at the time with the cast of his Chicago theater company.