The title is the Japanese code-word used to indicate that complete surprise had been achieved. Tora (虎, pronounced [tòɽá])) literally means "tiger", but in this case was an acronym for totsugeki raigeki (çªæ’ƒé›·æ’ƒ, "lightning attack").
The film was deliberately cast with actors who were not true box-office stars, in order to place the emphasis on the story rather than the actors who were in it.
Veteran 20th Century Fox executive Darryl F. Zanuck, who had earlier produced The Longest Day (1962), wanted to create an epic that depicted what "really happened on December 7, 1941", with a "revisionist's approach". He believed that the commanders in Hawaii, General Short and Admiral Kimmel, though scapegoated for decades, provided adequate defensive measures for the apparent threats, including relocation of the fighter aircraft at Pearl Harbor to the middle of the base, in response to fears of sabotage from local Japanese. Despite a breakthrough in intelligence, they had received limited warning of the increasing risk of aerial attack. Recognizing that a balanced and objective recounting was necessary, Zanuck developed an American-Japanese co-production, allowing for "a point of view from both nations." He was helped out by his son, Richard D. Zanuck, who was chief executive at Fox during this time.
Production on Tora! Tora! Tora! took three years to plan and prepare for the eight months of principal photography. The film was created in two separate productions, one based in the United States, directed by Richard Fleischer, and one based in Japan. The Japanese side was initially to be directed by Akira Kurosawa, who worked on script development and pre-production for two years. But after two weeks of shooting, he was replaced by Toshio Masuda and Kinji Fukasaku, who directed the Japanese sections.