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 fifth most commercially successful movie at the US domestic box office in 1961, grossing $25,381,407 (the most successful being, by a wide margin, another Disney classic, 101 Dalmatians (1961) at $153 million.
Most of the cars in the film are Ford (or their subsidiary Mercury) automobiles. Co-star Leon Ames owned several Ford automobile dealerships in the Los Angeles area in 1961 when the film was made. One was on Vermont near Beverly Blvd., Studio City, Torrance, Encino, and Redondo Beach. Another Leon Ames Ford dealership was in northern California in the city of San Rafael. Ames likely provided the cars.