Film debut of Robert Lansing.
Film debut of Lee Meriwether.
Scott and Tony work at the "Fairview Research Center." Fairview is the name of the production company that made this film.
A very young Patty Duke has a small cameo as one of the 4D Man's victims.
Jack H. Harris was able to begin production by using the advance he received for distribution of The Blob (1958).
In 1965 this film was recycled under the title "Master of Terror" as part of the "Master of Horror/Master of Terror" double feature. "Master of Horror" was the Argentine film Obras maestras del terror (1959), which had nearly half of its footage edited out with the remaining footage dubbed into English.
The large map on the police office wall says, "Delaware - Chester Counties, Pennsylvania".
The voice of Guy Raymond (Frank, the security guard) is dubbed by another actor.
The total number of non-practical effects shots of the 4D Man passing through objects in the entire movie is 14.