They fly to Cairo to meet Indy's friend Sallah, a skilled Egyptian digger and archaeologist. He takes Indy to an old Imam who decodes the markings.

Shia Labeouf was Speilberg's first choice to play Indy's son, Mutt Williams, after he impressed Speilberg with his performance in Holes.

Playwright Tom Stoppard provided most of the dialogue between Indy and his father, but didn't receive a writing credit for the film.

At the end of The Kingdom of the Crytal Skull, Indy and friends find thirteen crystal skeletons, one of which is missing its skull. When the skull is returned to the skeleton, the alien remains begin to reanimate.

Both actors were without their pants during the Zeppelin scene as it was filmed in a very hot studio and they didn't want to sweat too much.

River Phoenix had played the son of Harrison Ford's character in The Mosquito Coast in 1986 and Ford recommended him for the part of young Indy, stating that Phoenix looked more like him as a child than any other young actor working at the time.

According to Steven Spielberg, "What people really jumped at was Indy climbing into a refrigerator and getting blown into the sky by an atom-bomb blast... That was my silly idea. People stopped saying 'jump the shark'. They now say, 'nuked the fridge'. I'm proud of that. I'm glad I was able to bring that into popular culture."

German actor Klaus Kinski was offered the role of Major Arnold Toht but hated the script, calling it "moronically sh*tty".

D.R. Nanayakkara, who played the village shaman, spoke only Sinhalese and couldn't learn his lines from the English script. Speilberg would feed him his lines in English and Nanayakkara would repeat them, sometimes even miming some of Speilberg's hand motions.

The producers wanted to know if they could insure their rats, which had been specifically bred for the film, in case they were for some reason "indisposed". Their insurer, Fireman's Fund, underwrote the world's first insurance policy with a one thousand-rat deductible.