At the height of the film's popularity, Time Magazine printed the Disney Special Effects Department's recipe for Flubber, as used in the movie. It read as follows: "To one pound of salt water taffy add one heaping tablespoon polyurethane foam, one cake crumbled yeast. Mix till smooth, allow to rise. Then pour into saucepan over one cup cracked rice with one cup water. Add topping of molasses. Boil till lid lifts and says 'Qurlp'." It is not recorded whether this also carried the standard warning "do not try this at home".
The song "Medfield Fight Song" was written by Richard M. Sherman and Robert B. Sherman, the first of many they would write for Disney.
Three generations of the Wynn family act in this film: Ed Wynn; his son Keenan Wynn; and Keenan Wynn's son, Ned Wynn.