In 1929, a westbound Orient Express train was stuck in snow for five days at Çerkezköy, approximately one hundred thirty kilometers (eighty-one miles) from Istanbul, Turkey. This incident inspired the setting of the book and movie.
84-year-old Dame Agatha Christie attended the movie premiere in November 1974. It was the only movie adaptation in her lifetime with which she was completely satisfied. In particular, she felt that Albert Finney's performance came closest to her idea of Poirot (though she was reportedly unimpressed with his too-subtle mustache). The premiere was her final public appearance. She died fourteen months later, on January 12, 1976.
During promotion and publicity junkets, many of the stars admitted, independently of one another, that their chief reason for appearing in this movie was the chance to meet and work with the other cast members. In her memoir, Lauren Bacall recalled that the lure for most of the cast was getting to act on-screen with "Albie" Finney (Albert Finney).
The final scene, in which Poirot relates his solution to the crime, had to be shot countless times, as it required more angles than could be captured in a single take, and more cameras than could fit on the confining dining car set. The multiple takes were especially challenging for Albert Finney, whose uninterrupted monologue was eight pages long, but many cast members later recalled the tedium of sitting motionless for so long, maintaining their physical posturing for continuity, bolstered only by their professional drive to provide support for Finney's tour de force.
With so many suspects in the plot, and none of them expendable, director Sidney Lumet decided that the audience's odds of keeping the characters straight would improve if he cast a familiar face in each role. Lumet thought the best way to acquire an all-star cast was to sign the biggest star first. In 1974, that was Sean Connery, who Lumet had previously directed in La colina de los hombres perdidos (1965), Supergolpe en Manhattan (1971), and La ofensa (1973). Once Connery was attached, the remainder of the cast was set in a matter of weeks.