Producer Tomoyuki Tanaka offered Banno the opportunity to direct a Godzilla film shortly after working together on the Mitsubishi Pavilion at Expo '70.

Franchise veterans Kaoru Mabuchi and Ishirō Honda were tasked with assisting Banno with scripting and directing the film respectively.

Roger Ebert, Adam Wingard, and Nicolas Cage have hailed the film as their favorite in the Godzilla series.

The film was followed by Jun Fukuda's Godzilla vs. Gigan, released on March 12, 1972, Hedorah, an amorphous species of alien from the Horsehead Nebula, is transported to Earth by a comet.

After it sinks an oil tanker and attacks Dr. Toru Yano and his young son Ken, scarring the doctor, Hedorah's toxic existence is revealed to the public.

During the fight, however, several pieces of its new body are flung nearby, which then crawl back into the sea to grow anew and allow the monster to become even more powerful.

Ken, Yukio Keuchi, Miki Fujinomiya, and the other partygoers realize that Godzilla and Hedorah have also come to Mount Fuji for a decisive confrontation.

Hedorah sheds this outer body and takes flight to escape, but Godzilla propels itself through the air with its atomic heat ray to give chase.

Godzilla tears open Hedorah's dried-out body and exposes it to the electrodes again, dehydrating the pieces until nothing remains but dust.

[6] Producer Tomoyuki Tanaka offered Banno the opportunity to direct a Godzilla film shortly after working together on the Mitsubishi Pavilion at Expo '70.

[7] Due to Banno's inexperience, franchise veterans Kaoru Mabuchi and Ishirō Honda were tasked with assisting him with scripting and directing the film respectively.

Tanaka's declining health led to him being hospitilized for the majority of production, and Banno took advatuge of this to include a scene where Godzilla chases Hedorah by using his atomic breath to fly, which reportedly resulted in Tanaka loathing the film and refusing to give Banno another chance to direct a Godzilla film.

Director Banno initially conceived the idea for Godzilla vs. Hedorah after seeing cities like Yokkaichi covered in black smog and the ocean filled with foam from dumped detergent and formulated the story of an alien tadpole transforming into a monster as a result of the pollution.

Veteran Godzilla director Ishirō Honda was later tasked by producer Tomoyuki Tanaka to watch Banno's rough cut and provide advice.

This version features the original English dub produced in Hong Kong and by extension lacks the English-language song "Save the Earth".

According to Banno, Japanese critics generally ignored Godzilla vs. Hedorah, but those who did review it unanimously panned it, with the exception of the Yomiuri Shimbun.

[27] Later publications noted how reviewers conflicted about the scene where Godzilla uses his atomic breath to fly, although Nakano claimed that it was praised in the United States.

[29] Alan Cookman of the Evening Sentinel called the film a "curious—and curiously fascinating—Japanese import [that] is more of a tongue-in-cheek effort than you might imagine", venturing that six-to-twelve-year-olds would likely enjoy it most.

[30] He added that, "With wide screen, good colour and effects which include occasional lapses into animation and splitscreen, it is technically quite impressive.

[32] In 1998, a reviewer for Stomp Tokyo wrote that the film has "many obvious, crippling flaws" but praised the monster action, and commended the lack of reliance on stock footage and the effort put into the animated segments.

[33] In 2004, Stuart Galbraith IV, writing for DVD Talk, stated that the film "earns points for trying something new, to break away from what was fast becoming a tired formula.

"[34] In their 2018 book Japan's Green Monsters, Sean Rhoads and Brooke McCorkle offer an ecocritical assessment of Godzilla vs. Hedorah.

In a December 1996 interview with Cinefantastique, Nakano, the effects artist for the film, stated his thoughts on Godzilla vs. Hedorah:"Looking back, the movie seems kind of cruel and heavy handed.

Banno spent several years trying to acquire funding for a 40-minute IMAX 3D Godzilla film starring a new version of Hedorah called Deathla.

At the end of the film, a cliffhanger sequence features an illustration of Hedorah's tadpole form, followed by a black screen with red text stating "And yet another one?