Unlike its predecessors, the film did not receive a United States home media release until 2014, when it was released on Blu-ray along with the first two films. Its first US release was in 2003, when it was shown on the Syfy Channel in its English dub.
King Ghidorah's roar is a modified roar of the creature that appeared in Godzilla vs. King Ghidorah (1991).
Cretaceous King Ghidorah's growls are reused for Orga's roar in the Japanese version of Godzilla 2000 : Millennium.
In this film, King Ghidorah became the first and so far only kaiju to make his debut in the Godzilla series and later appear in a film without Godzilla.
The Rainbow Mothra prop was accidentally destroyed during filming of the scene where the Primitive Mothras encase him in a cocoon. The thinner used to create the Primitive Mothras' silk ignited during filming and set the Rainbow Mothra prop on fire, requiring the filmmakers to retrieve a new prop and film the scene again with it.