Originally scheduled for release in December 1963 but Burt Lancaster insisted the release date be postponed as it was too soon after the assassination of President John F. Kennedy. The same fate befell Il dottor Stranamore - Ovvero: come ho imparato a non preoccuparmi e ad amare la bomba (1964), which was also scheduled for a December 1963 opening.

The story is set in the "not too distant" future. While viewing slides of pictures taken at the last naval inspection, the date 1970 can be seen. Although likely overlooked by modern audiences, the movie has many futuristic items that would have seemed state of the art at the time of release. The wall projecting slide viewer, the television based teleconference equipment, even the digital time/date display at the Pentagon were all touches meant at the time of release to reflect a high tech environment of the near future.

The "Eleanor Holbrook" subplot was based on a real-life incident involving Gen. Douglas MacArthur. In 1934, the general sued journalists Drew Pearson and Robert Allen for libel. He dropped the suit when the defendants announced they intended to take testimony from Isabel Rosario Cooper, a Eurasian woman who had been the general's mistress.

This movie was never released in Brazil, due to the "coup-d'etat" organized by the military (1 April 1964). The generals who overthrew the government saw the film as uncomfortably close to what they did in real life and did not want Brazilians to be reminded of it, so they banned the film.

The White House wanted the film made and was very cooperative with the production. Press Secretary Pierre Salinger arranged for the production designer to have access to President John F. Kennedy's office and other rooms so they could be duplicated exactly at the studio.

One of seven films they made together, there has been a great deal of dispute over whether or not stars Burt Lancaster and Kirk Douglas were actually friends or simply business partners who tolerated each other for the sake of the films they worked on. Director John Frankenheimer said that they were friends but also that their friendship and working relationship was always strained by Douglas's alleged jealousy of Lancaster and Lancaster's rather legendary ego.

For security reasons, the Pentagon forbids camera crews near the entrances to the complex. John Frankenheimer wanted a shot of Kirk Douglas entering the building. So they rigged up a station wagon with a camera to film Douglas, in a full Marine colonel's uniform, walking up the steps of the Pentagon. The salutes Douglas received in that scene were real, as the guards had no reason to believe it was for a movie!

According to director John Frankenheimer, the Gen. Scott character is an amalgam of Gen. Curtis LeMay and Gen. Douglas MacArthur. The novel's co-author, Fletcher Knebel, has said that he based the character on disgraced and cashiered former army general Edwin Walker, who was forced out of the army after having been found to be using political material from various ultra-right-wing organizations he belonged to as "training manuals" in order to indoctrinate his troops in far-right-wing politics.

Kirk Douglas had originally signed to play Gen. James Mattoon Scott. Douglas eventually realized that his friend Burt Lancaster would be ideal as Scott, and took the less flashy role of Col. Martin "Jiggs" Casey after Lancaster signed on to the film.

An important plot point in the film involves the attempted coup taking place on the same day as the Preakness Stakes horse race. However, the seven-day timeline for the film would have had the coup taking place on Sunday while the Preakness is always run on a Saturday. John Frankenheimer said that the problem was solved by a scriptwriting acquaintance of his. This man worked as a script doctor and liked to gamble but wagered his professional services instead of money. Frankenheimer had won some work from the man and gave him the problem. The solution? In one scene a character walks by a poster which says "First Ever Sunday Running of the Preakness".

A liberal Democrat, Burt Lancaster was hesitant to take the role of Scott, as he felt the character and film unfairly vilified the conservative Republican party. Kirk Douglas persuaded him that the role of Scott was a morally ambiguous figure rather than a villain.

Paul Girard (Martin Balsam) meets Adm. Barnswell (John Houseman), commander of the 6th Fleet, in Gibraltar aboard his flagship, the USS Kitty Hawk, one of the newest and largest aircraft carriers in 1964. The scene was filmed in San Diego Bay, where the Kitty Hawk was actually flagship of the 7th Fleet based in the Pacific. The aircraft carrier USS Midway is in the background. The Midway is now a museum in San Diego while the Kitty Hawk was decommissioned (2009) and in the naval reserves. At time of her decommissioning, the Kitty Hawk was the second-longest serving U.S. Navy ship after the U.S.S. Constitution, "Old Ironsides," (commissioned 1797, and still on the Navy's list of active warships).

The director, John Frankheimer, wanted a more futuristic rifle for use by the military, given the movies, occurring in the near future and chose the Colt M16 for this purpose. The M16 was subsequently chosen as the replacement for the aging and overly heavy M14, then in service.

Kirk Douglas had been at a dinner with John F Kennedy, and JFK had asked him if he planned to make the novel " Seven Days in May " into a movie. When Douglas said " yes ", the president spent the next half hour telling him how great a movie it would be.

Spencer Tracy was originally announced for the role of the President.

John Frankenheimer had been in the Air Force and was very familiar with the Pentagon.

John Houseman's first feature film role, albeit uncredited. (Supposedly he had a small-but-deleted role in the 1957 British film "Ill Met By Moonlight," but this has never been confirmed.)

The film is set in the near future (relative to 1964), but the exact date is never given. While subtle clues in the film suggest that it is most likely set in May 1975, Senator Prentice's limousine has registration stickers on its license plate for 1969 and 1970.

Several cast members in studio records/casting call lists for this movie were not seen in the final print. These included: Leonard Nimoy, Victor Buono, and Bill Raisch.

Fifth of seven films that Kirk Douglas and Burt Lancaster made together.

One of the first full page ads for the movie's upcoming release appeared in the NY Times on November 22, 1963, the day of President John F. Kennedy's assassination.

Whilst preparing a dialogue scene with Frederic March, Burt Lancaster suddenly forgot his lines. He said to March that he knew them just before in his office. Then March asked Lancaster why he did not bring his office with him. Lancaster was vexed and, the day after, he knew his lines.

The film cast includes five Oscar winners: Burt Lancaster, Edmond O'Brien, Martin Balsam, Fredric March and John Houseman; and three Oscar nominees: Ava Gardner, Kirk Douglas and Ferris Webster.

Col. Casey's first name, Martin, is never spoken; he is always addressed (or referred to) by his nickname, "Jiggs". Casey's full name can be seen on the window that separates his office from the waiting room outside Gen. Scott's office. Interestingly, the meaning of "Jiggs" is never explained.

In the original novel upon which the film was based, Adm. Farley C. Barnswell's flagship is the USS Eisenhower, a good guess on the part of the novel's writers, Fletcher Knebel and Charles W. Bailey II: an aircraft carrier of that name would not be ordered until 29 June 1970, a full eight years after the book's publication.

During a briefing between Col. "Jiggs" Casey and Gen. Scott in Scott's Pentagon office, the second shot on the video screen, allegedly of B-47s taxiing at Wright Field during the January alert, is footage from the film Aquile nell'infinito (1955).

Both the book and the movie suggest that the story takes place in the near future -- that is, after the early 1960s. Using the day-date combinations featured on screen, as well as a conversation in which the next Presidential election is "a year and nine months" hence, the most likely setting for these events is May 1975.

John Larkin, who plays Col. Broderick, died suddenly less than a year after the film was released. Larkin had already shot many other films and TV episodes, which were released or aired posthumously.

Some film reference works (e.g., the multivolume set, "The Motion Picture Guide") incorrectly list Jack Mullaney's character as "Lt. Hough". "Hough" is the last name of this character in the novel upon which the film is based.

There are several instances of day and date being shown. Col. Casey mentions the day of the Preakness as May 18 (at 14:30 in the film). He later mentions that the Preakness is on Sunday (39:07). And again later, a TV screen is shown with the headline "1st Sunday Preakness" (1:49:16). This occurs 2 minutes after the flashing sign at the Offices of the Joint Chiefs of Staff reads Sun May 18 (1:47:52). The same flashing sign is used throughout the film to establish day and date: Mon May 12 (15:20) & Tue May 13 (25:13-23). There is also a chalkboard with Thu May 15 written on it and a cameraman at the lake films a sign with Fri May 16 on it. The dates are very clearly established as to be Monday May 12 through Sunday May 18. Since the film is placed in the near-future, the following years coincide with those dates: 1969, 1975, 1980, 1997. It is mentioned that "we been hating the Russians for a quarter of a century" (07:55), which is obviously an estimate, making the "near-future" either 1969 or 1975. Later, the president says that the next election is a year and 9 months away, which would be early 1971 or 1977, which is not when elections take place (they happen in November during years of multiples of 4). But there's also a shot of a license plate with tags for 1969 & 1970, which could be an error or deliberate. It's clear that the film makers have deliberately obfuscated the year in which these events take place.

Original composer David Amram's score was rejected and Jerry Goldsmith was quickly drafted in as a replacement.

Second of Frankenheimer's "paranoid" trilogy after The Manchurian Candidate and before Seconds.

The film takes place from May 12 to May 18, 1970.

Ava Gardner and Burt Lancaster appeared previously together in The Killers.

George Macready who plays Christopher Todd previously starred with Kirk Douglas in 1957's 'Paths of Glory.'

In General Scott's office there is a portrait on the wall of General Jimmy Dolittle, who was the man behind the audacious "Dolittle Raid" over Japan a few months after the attack on Pearl Harbor. While it had limited military value, its impact on both the Japanese and American public was profound. Clearly, Scott admires Dolittle's boldness, his organization and planning, and his willingness to act; all of which can be seen in Scott's character and actions.

When Casey is following the TV news anchor, his car parks behind a taxi. The advertisement on the back of the taxi is for the Preakness racetrack, promoting its first running on Sunday, May 10th.

When Senator Clark ( Edmond O'Brien ) is in Texas he is driving a Chevrolet Nova. This was a popular car and versions were also manufactured in Mexico and sold throughout Latin America. The name of the vehicle became quite a joke because in Spanish, "no va" means that the car "doesn't go."

In Eleanor's apartment there is a dark and gloomy abstract painting of an undesirable man leaning against a beached boat with a woman laying prostrate on the beach. Being the rejected mistress of General Scott, this painting clearly represents the failure of their relationship. Meanwhile on the wall nearby there is an elegant series of light and breezy images that represent Eleanor herself.

The President refers to General Walker, likening him to Joesph McCarthy and General Scott. Major General Edwin Walker was a right wing extremist who ran afoul of President Eisenhower because of his extremist views, his accusations of his superiors and others, including Eleanor Roosevelt and and President Harry S. Truman as being communist sympathizers. As with General Scott, he also violated the Hatch Act by using his military authority to influence the votes of those under his command. After he left the service he was a key instigator in the violent riots at the University of Mississippi in 1962, attacking the right of a black student to enroll in the university.