Audrey Hepburn and Albert Finney were required to "direct" themselves in several sequences where they were shown inside of a moving automobile. They pushed the camera's buttons while director Stanley Donen rode alongside them in another car.
Audrey Hepburn narrowly missed getting an Oscar nomination for this film. The Academy had to choose between her performances in this film and in Wait Until Dark and chose the latter.
Audrey Hepburn was Stanley Donen's first and only choice for the role of Joanna. When he sent her a treatment, she turned it down because the avant-guard style of filmmaking didn't appeal to her, as she had already done one like it before that hadn't been successful (it was probably Paris - When It Sizzles). When he tried again and sent her a whole script, she loved it and agreed to do it.
Audrey Hepburn was afraid of water, so the scene in which Mark throws Joanna into the water had to be done with some divers standing just barely outside the camera range. One take was ruined because the diver jumped in too save Audrey too quickly.
Jacqueline Bisset is partially dubbed by another actress. Soon after filming, Bisset received a role in a major Hollywood film. She left England and was therefore unavailable when it came time to re-dub some of her lines.
Paul Newman and Michael Caine were director Stanley Donen's first two choices for the role of Mark Wallace.
Paul Newman turned down the role of Mark Wallace.
Henry Mancini said that although the scoring was the most difficult in his career, the music he composed for this movie was always his favorite.
According to Stanley Donen on the DVD audio commentary, nobody wanted to film the scene where Mark confronts Joanna's infidelity at the cliff side café because many found it personally painful and realistic.
Average Shot Length = ~4.5 seconds. Median Shot Length = ~4.4 seconds. Both values are quite fast, and demonstrate the experimentation with faster cutting rates during the mid to late 1960s. For example, even a noted fast cutter like Sam Peckinpah would take until 1969 to produce a film (_Wild Bunch,The (1969)_) that is cut faster than _Two For The Road (1967)_.
Originally slated to be produced by Universal. Taken over by Richard D. Zanuck and David Brown from 20th Century Fox.
Several biographies of Hepburn state she was very nervous shooting her first nude scenes for this film, particularly a skinny dipping sequence. If such a scene was shot, it didn't end up in the final print.
The "present day" car (a Mercedes 230) was director Stanley Donen's own personal car.
The poem recited to Caroline in the car, "The bumble-bee, the bumble-bee/ He flew away from the tulip tree..." is from 'Tommy's First Speaker for Little Boys and Girls' by Thomas W. Handford, published in 1886