American Broadcasting Company (ABC) subsidiary Selmur Productions announced in the 25 May 1966 Var that it had entered a co-production deal with Benedict Pictures (a subsidiary of Henry G. Saperstein Enterprises), Mifune Productions, and Toho Film to make Japanese star Toshiro Mifune’s second American picture, Hell in the Pacific, later that year. Toho executive Tomoyuki Tanaka, Selmur vice president Leon I. Mirell, and Saperstein Enterprises’s Reuben Bercovitch, who wrote the story, were set to co-produce the film. Mirell and Selmur Productions president Selig J. Seligman flew to England to talk with Lee Marvin about joining the film, the 13 Jul 1966 Variety noted, but Mifune had a falling out with Toho the following month, halting the project indefinitely, according to the 24 Aug 1966 DV. Tanaka and Mirell were not credited in the eventual film.
       Hell in the Pacific was back in development a year later, the 16 Aug 1967 Var reported, as one of three films on ABC’s production schedule. John Boorman was slated to direct, Mifune and Marvin would star, and filming would begin in three months. The 25 Aug 1967 and 29 Aug 1967 editions of DV mentioned that Selmur Productions executive Art Stolnitz had gone location scouting in Hawaii with Reuben Bercovitch and unit production manager Lloyd Anderson. The 22 Aug 1967 LAT stated that William Ludwig wrote the screenplay, based on a story by Bercovitch and Tadashi Akiyama, but neither Ludwig or Akiyama was listed in final credits.
       Lee Marvin, who had won an Academy Award two years earlier for Cat Ballou (1965, see entry), was contracted to receive a $750,000 salary against ten percent of the gross for his role in Hell in the Pacific, according to the 11 Oct 1967 Var.
       Principal photography began 2 Jan 1968 in the Palau Islands of Micronesia in the South Pacific and ended four months later, 8 Apr 1968, on the island group’s Koror Island, as mentioned in the 5 Jan 1968 and 9 Apr 1968 editions of DV and in the 11 Feb 1969 NYT. In a 31 May 1968 LAT interview, Lee Marvin admitted that there was dissension during the cast and crew’s four-and-a-half months on the remote islands. Mifune and Marvin could not speak each other’s language and had to communicate off-screen in broken Spanish. Half the crew was American, and the other half Japanese from Mifune’s film company. Mifune often feuded with British director John Boorman, accusing him of being unprofessional, and Bercovitch had no previous production experience. Everyone lived on a Liberian freighter with a Chinese crew and a captain who mutinied against the production until the ship’s crew forced him to quit. What saved the movie, Marvin claimed, was that he and Mifune were the only actors, and got along despite their language differences. Also, according to the 16 Jan 1968 DV, Marvin’s friends, at his request, shipped him 100 frozen Mexican dinners to relieve the steady Chinese diet aboard ship.
       Working titles included Two Soldiers--East and West and The Enemy.
       The $5-million film premiered, for the purpose of Academy Award consideration, at the Picwood Theater in West Los Angeles, CA, for a week’s run, beginning 18 Dec 1968, according to the 30 Nov 1968 and 17 Dec 1968 editions of the LAT. A "world premiere" was set to take place in Tokyo, Japan, on 21 Dec 1968, with both stars attending. The Picwood would again host the film beginning on 6 Feb 1969. The 11 Feb 1969 NYT announced that Hell in the Pacific opened the previous day at Manhattan’s Penthouse Theatre. The film opened wide in thirty-three theaters around the New York City area in Apr 1969, according to the 16 Apr 1969 Var, and made $215,000 the first week. Reviews were mixed.
       In a 30 Dec 1968 LAT interview, Toshiro Mifune claimed the film “had nine endings to choose from,” but everyone finally agreed on the best one. However, the 28 Apr 1969 DV reported that executive producer Henry G. Saperstein changed the ending, and director John Boorman’s agency “registered a beef with ABC,” insisting that the new cut “damaged the picture.” In his original ending, the two characters “poignantly” made their goodbyes and went their separate ways, “each going back to his own world.” Saperstein reportedly added “stock footage of an explosion,” leaving the audience with the impression both men were killed. Boorman, who was home in London, England, awaiting the film’s 1 May 1969 European premiere there, was told his original ending would not be restored.