For her few scenes with Sir Michael Caine, Shelley Winters couldn't understand his dialogue at all, due to his strong Cockney accent, and had to wait until her leading man stopped moving his lips before responding with her lines.
This film cost only £500,000, about which director Lewis Gilbert famously quipped that the sum was "the sort of money studio executives spend on cigar bills."
On its original release, the film had an all-instrumental soundtrack, by Sonny Rollins. The Oscar®-nominated song, by Burt Bacharach and Hal David, was added for the American release, and to a U.K. re-release. For the U.K. re-release, the song was sung by Cilla Black over the end credits, which went to number nine on the British charts. For the U.S. release, the song was originally to be sung by Dionne Warwick over the end credits, but was replaced at the last minute by the version sung by Cher. Ironically, Warwick's version outperformed Cher's on the Billboard charts. Burt Bacharach produced Black's version, although Sir George Martin insisted his be the only name to be credited.
Several well-known actors (including Richard Harris, Laurence Harvey, James Booth, and Anthony Newley) turned down the title role, due to the then taboo subject matter of abortion. Despite having played "Alfie" on Broadway, Terence Stamp categorically declined to reprise the role on film, thus giving his good friend, and then roommate Sir Michael Caine, the breakthrough role of his career.
First of four Sir Michael Caine movies also featuring Denholm Elliott. The remaining three films are: Trop tard pour les héros (1970), Un pont trop loin (1977), and Bruits de coulisses (1992).