- Creator Killer: Hal B. Wallis later conceded in a letter to John Wayne that the choice of Stuart Millar as director had been a mistake. This was Millar's second and final film.
- Dawson Casting: Katharine Hepburn was considered by some to be too old for her role. In fact, Jon Lormer, who played her father, was only one year older than her.
- Dueling-Stars Movie
- Franchise Killer: There had been plans for a third film featuring the character Rooster Cogburn, to be entitled Someday, but it was canceled when this movie proved to be only a moderate hit at the box office. In addition Paramount Pictures cited John Wayne's age as too old to carry a successful movie, and waning audience interest in westerns. There would be a made-for-TV sequel featuring Warren Oates as Cogburn years later, but without any direct connection to this film or its predecessor.
- The Other Darrin: H.W. Gim, who played the original Chen Lee, Rooster's Chinese companion, had died in the intervening years since the original film so the role was taken over by Tommy Lee, who died the year after this film was released.
- Refitted for Sequel: The conversation that Rooster has with Wolf, about the small gun he loans him, is taken directly from an unused line of dialogue in the novel True Grit.
- Wag the Director: Director Stuart Millar insisted on so many takes that eventually John Wayne snapped, "God damn it Stuart, there's only so many times we can say these awful lines before they stop making any sense at all."
- Katharine Hepburn was bemused by Wayne's tendency to argue with everybody, especially the director, during filming. At the party to celebrate the last day of filming she told him, "I'm glad I didn't know you when you had two lungs, you must have been a real bastard. Losing a hip has mellowed me, but you!"
- What Could Have Been:
- John Wayne originally wanted Ingrid Bergman as his co-star. He then suggested the character should be made younger and Mary Tyler Moore should be cast, saying he feared audiences would not want to see a movie where both stars were elderly. Bette Davis, Maureen O'Hara, Vanessa Redgrave and Maggie Smith were also considered.
- If Wayne had been too ill to play Rooster Cogburn in this film, the part was going to be offered to Marlon Brando. Other choices were Charles Bronson, Richard Burton, Kirk Douglas, Clint Eastwood, Gene Hackman, Charlton Heston, Rock Hudson, Burt Lancaster, Steve McQueen, Robert Mitchum, Paul Newman, Gregory Peck, Anthony Quinn and George C. Scott.
- You Look Familiar: Strother Martin, who portrays Shanghai McCoy in this film, also appeared in True Grit, playing Col. Stonehill, the sarcastic horse trader who is bested in a deal by Mattie Ross.
Trivia / Rooster Cogburn