*The black and white scenes of Kansas were filmed last. This provides contrast to colorful Oz, which is a good thing since the Technicolor cameras had already been moved to the "Gone With The Wind" set.
*Bert Lahr, Jack Haley and Ray Bolger had to suck lunch through a straw as they couldn't eat in those costumes.
*The Cowardly Lion's tail was worked by a technicians on an overhead walkway.
*Buddy Ebsen was originally cast as the Tin Man, but developed a severe allergic reaction to the silver paint make-up, and needed to be hospitalized. Less than two weeks after the filming began, he was replaced by Jack Haley.
*The Horse of a Different Color couldn't be actually painted because of Animal Rights concerns. So they used colored, flavored jelly - which the horse kept licking off.
*It took 20 guys a week to set up the 40,000 wire poppies.
*The "oil" that was used to lubricate the Tin Man was not really oil. It was discovered that oil would not photograph well, so they used chocolate syrup instead.
*Adriana Caselotti (the voice of "Snow White") was paid $100 to sing one line - "Wherefore art thou, Romeo?", in "If I Only Had a Heart".