A young Barbra Streisand was first considered for the role of the American stowaway Barbara, but was then deemed "too big" (as in too famous) for the part and would take the limelight away from Cliff Richard.
Melvyn Hayes dyed his hair blond for this film. As he had returned to his natural colour by the time "Bachelor Boy" was filmed, he wore a wig. This was the shot chosen for most of the publicity material.
London Transport cooperated fully with the film, lending the film company three buses to act as RT1881, and more notably allowing filming to take place at the Aldenham Bus Overhaul Works during the summer shutdown. The film shows actual working equipment, including the buses being carried about by cranes and rotated on body tilter mechanisms. In one shot that would today undoubtedly be prohibited both by modern workplace safety regulations and a film's insurance underwriters, Cliff Richard himself rides 20 feet in the air on a bus's rear platform as the bus body is carried through the works by overhead crane.