Some of the designs for the Godzilla suit were similar save for the texture of the monster's skin. One Godzilla's skin was very warty, while another was more like that of an alligator. The final design, giving Godzilla his familiar rocky hide, was meant to suggest that the nuclear bomb blasts which awakened him had burned him.

Special Effects artist Eiji Tsuburaya originally wanted Godzilla to be a giant octopus. He would later get his wish of having one though in the movies King Kong vs. Godzilla, a deleted scene in Frankenstein Conquers the World, and The War of the Gargantuas, where the octopus would meet his end. It was even given the name Oodako. The octopus also made an appearance in the TV series Urutora Q, and was up for consideration to be Godzilla's opponent in Godzilla: Final Wars.

Stop motion animation in the style of King Kong was rejected because of the time it would take and the subsequent cost. Also, according to special effects director, Eiji Tsuburaya, there was simply no one in Japan who was skilled and experienced in doing that kind of stop motion animation.

The building whose clock tower Godzilla tears off is the Wako department store. It was completed in 1932 in the Ginza district and still stands today, clock tower intact.

The electrical towers that Godzilla melts with his radioactive breath were actually made of wax. The special effects crew melted them by blowing hot air on them, as well as shining hot studio lights on them for the white-hot effect.

The film received a Japanese Academy Award nomination for Best Picture, but lost to Seven Samurai. However, the film did win the award for Best Visual Effects. It is the only Godzilla movie to receive a nomination for Best Picture.

The first made Godzilla suit weighed around 200 pounds, making it rather difficult for the performer (Haruo Nakajima) to move around in.

The idea for Gojira (aka Godzilla) was spawned after producer Tomoyuki Tanaka was forced to cancel a planned Japan-Indonesia co-production called Eiko kage-ni (Behind the Glory). The story was inspired by a real-life nuclear accident in which a Japanese fishing boat ventured too close to an American nuclear test and was contaminated.

The movie's opening scene was inspired by the Lucky Dragon incident, where the fishing boat known as the Lucky Dragon strayed too close to what was named the most powerful nuclear test ever and was contaminated with radiation. A crew on board a fishing boat, going about their normal day, suddenly a bright flash of light catches their attention, and they are soon bombarded with radioactivity. The only difference is that the boat catches fire and sinks in the movie. If you look closely at the life preserver, you will see the marking "No. 5". This was a reference to the ship Lucky Dragon No. 5, which was one of the inspirations for the film.

The name Gojira is a combination of the Japanese words for gorilla (gorira) and whale (kujira). The monster was so named because his original design was that of a gorilla-whale monster, which is recounted by people who worked on the film. 'Shigeru Kayama' (who was hired by Tomoyuki Tanaka to write the original story) recounted in a book of memoirs he published in Japan, that Tanaka told him the creature would be a sea monster that was "a cross between a whale and a gorilla". After producer Tanaka saw the American monster film The Beast from 20,000 Fathoms, he got the idea to turn Godzilla into a dinosaur monster. Despite the physical change the name of the monster was kept. There has always been a legend that Godzilla was named after a hulking man nicknamed Gorilla-Whale who worked at Tôhô, but this is untrue. Not only is there no evidence of this man even existing, but the various stories about him kept changing through the years (he worked as a stagehand, he worked as a PR man, etc.). According to Kimi Honda, wife of Ishirô Honda, the Gorilla-Whale man was just an inside joke between her husband and various others on the Tôhô lot - specifically produc

The scenes of Godzilla underwater were filmed "dry for wet" with an aquarium (complete with fish) placed between the camera and the monster-suited Haruo Nakajima. Actual underwater footage of divers was combined with additional "dry for wet" footage of Ogata and Serizawa.

The scenes of the troops going to the coast to face Gojira were actual Japanese Defense Force troops. They were on maneuvers when Honda shot the footage of them.

The simultaneous production of this film and Seven Samurai nearly forced Tôhô Kabushiki Kaisha into bankruptcy.

The sound department tried numerous animal roars for Godzilla but felt they were unsuitable for an animal of such immense size. Akira Ifukube came up with Godzilla's roars by rubbing a coarse, resin-coated leather glove up and down the strings of a contrabass (double bass), and reverberated the recorded sound. Also, Godzilla's thunderous footsteps were made by beating a kettle drum with a knotted rope.

The workload on the special effects department for this film, as well as the other productions underway at Toho, resulted in a shortage of necessary personnel. Special effects director Eiji Tsuburaya was able to get his son, Hajime Tsuburaya, his first job in the industry as a camera assistant.

There was a common misconception that the name "Godzilla" was Americanized by its US distributors from Gojira. The name Godzilla was actually the idea of Tôhô and its international sales division. "Godzilla" or "Go-dzi-la" is the proper pronunciation of "Gojira" in its native Japanese and Godzilla was described by Tôhô as "Godzilla" in their 1955 English language sales catalogue, a full year before finding an American distributor. The film even played briefly in Japanese-American owned theaters in Los Angeles and New York that year under the title of "Godzilla", before being picked up by Transworld and released in an Americanized version featuring Raymond Burr that following year as Godzilla, King of the Monsters!. Tôhô has since been the sole owners of the name Godzilla.

There was another ending considered for the film: a scene with Emiko and Ogata (presumably after they had gotten married) flying over Tokyo Bay and throwing a floral wreath in the water in memoriam of Serizawa. However, that ending was scrapped because Honda felt that they had already paid tribute to Serizawa after he sacrificed himself to destroy Godzilla.

There were supposed to be more scenes filmed on Odo Island. One was to have Dr. Yemane, Emiko and Ogata visit the graves of those that died during the typhoon when Gojira (Godzilla) came ashore. That scene was to have helped to establish the previous relationship between the Yemani's and Shinkichi's family. Another scene was to have been filmed on the beach and in that one Emiko and Ogata become frightened when the get their first glimpse of Gojira (Godzilla) as they see his tail splashing in the water.

There were three cables coming out of the back of the costume. Two were for the operation of the eyes, and one was for the operation of the mouth. Kaimai Eizo was responsible for the movement of the eyes and the mouth. Batteries were installed in the Godzilla costume that was made for Godzilla Raids Again. They were for the operation of the eyes and the mouth. The batteries made the costume even heavier than the one that had been constructed for the first Godzilla film.

This was Akira Takarada's first starring role after appearing mainly in small supporting roles.