Ingrid Bergman agreed to do the film with the script sight unseen in order to work with her friend Cary Grant again.
The casting of Cary Grant and Ingrid Bergman as slightly older and wiser lovers had greater relevance to 1958 audiences. Grant was on the third of his five marriages, while Bergman had ridden the waves of scandal following her adulterous relationship with Italian director Roberto Rossellini.
When director Stanley Donen asked Cary Grant if he would do this film, Grant said only if Ingrid Bergman would be his co-star. Bergman was committed to doing The Inn of the Sixth Happiness (1958) which was to be filmed in the UK, and a theatrical production in Paris, so this film was moved to Elstree Studios in England.
In a contemporary article in the Hollywood Citizens-News, the split screens with Philip and Anna in bed in separate cities was done by constructing separate bedrooms on a single soundstage at the studio and utilizing separate camera and sound crews, but synchronizing their actions.