After it was discovered that Mie Hama playing Kissy Suzuki couldn't swim, Sean Connery's then wife, actress Diane Cilento, doubled for her in her swimming scenes wearing a black wig. Some reports claims that Hama could not do them because of stomach cramps.

Before the title sequence there is an outdoor shot of a Russian radar station, where US and Soviet leaders are having a crisis meeting. This was in fact filmed at Magerø in the Oslo fjord in Norway (uncredited), to get a Nordic winter light feel to the footage. The dome-shaped radar station is still in operation today, run - as it was then - by the Norwegian military.

Bond producer Barbara Broccoli grew up in the behind-the-scenes world of James Bond and as a child during location shooting in Japan for this movie she caught a fever from the Japanese custom of sleeping on the floor. James Bond star Sean Connery's star status provided him with a comfortable bed and he generously relinquished it so she could properly fight her illness.

Despite being a major character in this film, Kissy Suzuki's name is never mentioned once on screen. Nor do we learn Aki's last name. Both situations are unique among major Bond film characters.

Director Lewis Gilbert originally turned down the directing job on this movie.

Eon productions considered hiring Gerry and Sylvia Anderson's production company - the company that made their Supermarionation shows such as Stingray, Thunderbirds, and Captain Scarlet and the Mysterons - to help out with the film's SFX work; it would not be until The Man with the Golden Gun that Derek Meddings, chief FX technician for the Andersons, would go to work on a Bond film.

Ernst Stavro Blofeld was named after Tom Blofeld with whom James Bond creator Ian Fleming went to school at Eton. His son is cricket commentator Henry Blofeld. Blofeld's birth-date as given in the novel is the same date as Ian Fleming's birthday which is 28 May 1908.

First Bond film in which 007 does not visit Britain at all. Because of this plot point, M and Miss Moneypenny are given portable offices - a gimmick reused in The Man with the Golden Gun, The Spy Who Loved Me, and Moonraker.

First Bond film not to show the MI6 headquarters.

First film to show James Bond in his Royal Navy uniform and to clearly indicate that he holds the rank of Commander.

Footage of the US Jupiter spacecraft in the film is actually film of the real Gemini spacecraft which flew between 1965 and 1966. The Gemini spacecraft were used for testing of such activities as EVA and docking for the Apollo space project which was to follow. Ironically, the Soviet spacecraft in the film were called Gemini (the name of the real life US spacecraft) and their designs were based on inaccurate UK perceptions of what the Russian Voskhod and Vostok spacecraft looked like, something which was not known until 1967 after the film had wrapped shooting.

In a rather curious train of events, Robbie Williams famously sampled the intro to this title song (as sung by Nancy Sinatra) for his no. 1 hit song "Millennium" (1998). After YOLT wrapped, Sinatra and father Frank Sinatra duetted on the song "Somethin' Stupid" topping the US and UK charts in April 1967. Thirty four years later Robbie Williams and Nicole Kidman duetted on the same song topping the UK charts (2001).

In order to gain some measure of authenticity for the team of stuntmen who would double as Ninja in the climactic battle in the volcano, the producers enlisted the help of Japan's only practicing Ninja master, 34-year-old Masaaki Hatsumi who had inherited the tradition from his then retired teacher Toshitsugu Takamatsu. Both Takamatsu and Hatsumi had advised during the production of the first two of the Japanese "Shinobi No Mono" Ninja Assassins series of films produced in Japan between 1962 and 1966, and not only did the film provide an opportunity for Hatsumi to give more credibility to the Ninja characters, but also allowed him a few brief moments of screen time aboard Tiger Tanaka's private train, as he interrupts Bond and Tanakas Sake discussion to announce that the photographs are ready for viewing.

In Sept. 1972, United Artists was widely exhibiting this film on a double bill with Thunderball with the tag line "The 2 Biggest Bonds of All".

In the article "The Oriental Beauties of You Only Live Twice", published with a pictorial in the June 1967 issue of "Playboy" Magazine, screenwriter Roald Dahl claimed that he assembled his script to a formula already established in the previous films in the series, and that he never took the script seriously. In fact, he said that the formula was strictly enforced by the producers, who would broach no deviation. This was not the first connection of the film with the magazine: An excerpt of Ian Fleming's original novel had appeared in the April 1964 issue of "Playboy".

In the German-dubbed version Spectre is called Spectre for the first time; it had the name Phantom in the previous movies.

In the novel, Ian Fleming describes Blofeld's hide-out as being a castle on the coast. Ken Adam discovered that this could never be. The Japanese never built their castles directly on the coast for fear of typhoons. Hence the creation of the elaborate volcano set.

James Bond does not drive a car in this film. This is the only EON Productions James Bond film to date in which James Bond does not drive a vehicle.

James Bond participates in a Japanese wedding ceremony in the film. Mercifully, he uses a false name, otherwise this would mean he would have been still married under Japanese law when he wed Tracy di Vincenzo in the next film, On Her Majesty's Secret Service

Last Bond film to make extensive use of voice dubbing. In this film and most of those made previously, many of Bond's leading ladies and villains were overdubbed by other actors. This practice rarely occurred in future Bond films.