The working titles of this film were Justice, Justice Brown and The Kid from Outer Space. Brief snippets of the songs "Sweet Genevieve" and "Beautiful Dreamer" are heard in the film. According to Hollywood Reporter news items, Thelma Ritter was originally cast as "Amelia Brown." A February 1953 Daily Variety news item reported that the film, which was to be produced by Twentieth Century-Fox, was to be the "tee off of a series" starring Ritter. The property was taken over by Leonard Goldstein's Panoramic Productions, and October 1953 Hollywood Reporter news items announced that after Ritter "bowed out" of the production, Marjorie Main was considered to replace her, and that Jeffrey Hunter and Gloria Gordon had been added to the cast.
       Due to production delays caused by the casting of the lead role, Panoramic was forced to shoot "one day of inserts" on November 14, 1953 in order to "insure [child actor George] Winslow's services" to the studio for the picture. Winslow was under contract to Fox at the time of production. According to a November 3, 1953 Hollywood Reporter news item, comic Lenny Bruce was specifically hired "to strengthen comic sequences" in the film's screenplay. A modern source states that the costume worn by the uncredited spaceman in the film was the same as that worn by the extraterrestrial character "Klaatu" in Fox's 1951 picture The Day the Earth Stood Still.