This Island Earth

In a magazine article, the special effects department admitted that the "mutant" costume originally had legs that matched the upper body. They had so much trouble making the legs look and work properly they were forced by studio deadline to have the mutant wear a pair of trousers. Movie posters show the mutant as it was supposed to appear.

In one of the scenes in the film E.T. The Extraterrestrial, a television is on in the background. This Island Earth is shown on the TV, where a flying saucer is about to swallow up a light aircraft.

The Earth miniature used in the effects shots was also used to make the 1950's-1980's "Earth in Space" Universal Pictures fanfare opening.

With the newfound popularity of 20th Century Fox's Cinemascope and other widescreen processes in the mid-1950s, Universal Pictures commenced to develop its own widescreen technology (which would eventually be known as Technirama). As Technirama would not be perfected until 1956, in the interim approximately 50 Universal films released between 1955 and 1957 (including This Island Earth (1955)) would be shot at full-frame (1.37:1) but carefully composed and photographed in such a way to allow theaters to comfortably exhibit these films at 2:1 (with matting at the top and bottom of the projected image to produce a widescreen effect). Essentially, the same print could be sent to any theater allowing it the option of projecting either a full-frame presentation (in older theaters) or a cropped presentation (for those theaters that had been recently renovated for widescreen exhibition).

In interviews to promote the film, actors Jeff Morrow and Rex Reason said that when scenes involving the mutant came up during the premiere, it took every ounce of restraint for them not to sneak out. They were extremely embarrassed by the mutant costume, which they likened to a giant bug. They felt that the mutant completely ruined an otherwise decent film.