In an undercover mission, Major Sloane kills Professor Ragheeb, an ancient hieroglyphics expert at Oxford University, and steals a hieroglyph-encrypted message. Sloane then asks Professor David Pollock, who has taken over Ragheeb's class on hieroglyphics, to meet with shipping magnate Nejim Beshraavi on a business matter. David declines but changes his mind after being forced to enter a Rolls-Royce Phantom IV, where he meets Middle Eastern Prime Minister Hassan Jena, and his ambassador to Great Britain, Mohammed Lufti. Jena asks David to accept Beshraavi’s offer of employment.
David meets Beshraavi, who asks him to decode the inscription on the piece of paper Sloane stole. David is attracted to Beshraavi’s girlfriend Yasmin Azir, who tells him that Beshraavi had Ragheeb killed and will do the same to him once he decodes the message. Their conversation is interrupted by Beshraavi. David keeps hidden until Sloane brings it to Beshraavi's attention that David and the cipher are missing. Overhearing the conversation, David wraps the cipher in a candy in his pocket, among others, a red one with the number “9.” As Beshraavi’s men search for David, Beshraavi demonstrates to one of Yasmin’s employees, Hemsley (Jimmy Gardner), that he can buy people for their loyalty or else exact extreme revenge. Forced to show himself, David seemingly abducts Yasmin. They flee from one of Beshraavi’s henchmen, Mustapha (Larry Taylor). In the course of the chase, Mustapha and David struggle at the zoological gardens, when another man intervenes and kills Mustapha. He identifies himself as Inspector Webster (Duncan Lamont) with CID. When a guard approaches, Webster kills him before revealing that he is working with Yasmin. Webster knocks David unconscious.
David awakes in a moving panel van in the presence of Webster, Yasmin, and another of Yasmin’s boyfriends, Yussef Kassim (Kieron Moore), who is looking for the cipher. David, seeing the bag of candies on a shelf in the van, tells Yussef that Beshraavi has the cipher. They use truth serum on David, after which he talks what they believe is gibberish about the number “9”. Believing that he was telling the truth about Beshraavi, Yussef tells Yasmin to work on Beshraavi while they throw David out of the vehicle.
The next morning, Yasmin arrives home and tells Beshraavi that Yussef, for whom the cipher was originally intended, killed David and Mustapha but does not yet know the coded message. While Yasmin believes Beshraavi has the cipher, Beshraavi states that David must still have it. Later, Yasmin bursts into David’s apartment as he finishes a phone conversation with Jena. She convinces him that she hates Yussef and pretends to help him because his boss, a General Ali orchestrating a military takeover, has her mother and sisters hostage. She tells him he needs to crack the cipher so she can report back to the embassy, which will ensure their safety.
David and Yasmin go to the construction site Yussef uses as his front. They spot the van, but Webster takes the candies to eat. Following him, David and Yasmin watch him discover the cipher and telephone someone from a phone booth; they learn that person is Beshraavi, with whom Webster is entering into a double cross against Yussef. Beshraavi and Webster are to meet at the Ascot racetrack.
At Ascot on race day, Yasmin is with Beshraavi, while David searches for Webster. David and Yasmin make plans to meet at 9 that evening at Trafalgar Square after David gets the cipher from Webster. At the track, David spots Webster rendezvousing with Sloane, who hands over an envelope of money. David knocks the cipher out of Webster’s hand, and the envelope floats into the track with the horses approaching. As David and Webster struggle, Sloane attempts to stab David, but accidentally kills Webster. David runs onto the track and retrieves the cipher just before the horses gallop by.
David makes copies of the cipher, mailing the original to himself for safekeeping. At a newsstand he then notices newspaper headlines which implicate him as Webster’s killer.
David believes that Mrs. Ragheeb (Malya Nappi) may know something important about the cipher. He visits her at home and shows it to her, also giving her the news that her husband has been killed (she was living secluded and hadn't heard). Mrs. Ragheeb examines the cipher and tears it up in frustration, implying that she knew that Ragheeb was working on something dangerous. David also tells her that he is working with Yasmin, whose mother and sisters are in danger at the hands of General Ali. Mrs. Ragheeb replies that Yasmin is lying, in that she has no mother or sisters, only a father who happens to be General Ali himself.
That night, David hops into Yasmin’s car and they drive off. Angry at Yasmin’s deceit, David lies, telling her that he does not have the cipher with him but has decoded the message, and makes up a nonsense meaning to tell her. She relays that information to the embassy via telephone regardless. David and Yasmin arrange to meet later at the hotel where he is staying. After she drops him off, David flags down a taxi and follows her to Yussef’s construction site. David sees Yussef operating a wrecking ball, swinging it repeatedly attempting to kill Yasmin. David rushes to save her, and Yussef is electrocuted to death by a live wire.
David determines that the hieroglyphics are simply a version of the nursery rhyme "Goosie Goosie Gander." He then looks for secret writing on it, such as invisible ink, and getting it wet the ink washes away, leaving a speck which he determines is a microdot. At a scientific store they examine the dot under a microscope and it reads "Beshraavi plans assassinate Jena twelve thirty June eighteenth" which is in 20 minutes. They don't know where to go, until Yasmin sees on a newscast that Jena has just landed at the airport. David and Yasmin make it to the airport a few minutes before 12:30, where David shoves past security guards to Jena, who is beginning a welcoming speech. David knocks Jena to the ground just as bullets from Sloane's machine gun land where Jena was just standing. However, Lufti then shoots Jena dead with a pistol. Yasmin whisks David off and convinces him that the man who was just shot is only an imposter of Jena.
They discover that the real Jena was abducted by Beshraavi and locked in a trunk in the back of a truck. David and Yasmin hide in the truck and free Jena just as the van arrives at Beshraavi's country estate. David, Yasmin, and Jena quickly escape on horses from his stables, being pursued through crop fields by a farm combine with sharp blades. Beshraavi and Sloane also pursue them in a helicopter. As they cross the disused Crumlin steel-girder railway viaduct David drops a wooden ladder down into the rotors of the helicopter as it passes underneath, causing it to crash and burn.
David and Yasmin end up in romantic bliss, on a rowboat back at Oxford.Gregory Peck — Prof. David Pollock
Sophia Loren — Yasmin Azir
Alan Badel — Nejim Beshraavi
Kieron Moore — Yussef Kasim
Carl Duering — Prime Minister Hassan Jena
John Merivale — Maj. Sylvester Pennington Sloane
Duncan Lamont — Kyle Webster
George Coulouris — Ragheeb
Ernest Clark — Beauchamp
Harold Kasket — Mohammed Lufti
Director/Producer Stanley Donen wanted Cary Grant for the role of Pollock. Donen worked with Grant in his previous film Charade and the dialogue for Pollock was written with Grant in mind. Donen later estimated that $400,000 was spent on the script alone and cinematographer Christopher Challis recalled that the film went through several rewrites. With Peck and Loren already contracted to do the film, Challis recalled that Donen told him "Our only hope is to make it so visually exciting the audience will never have time to work out what the hell is going on".
Arabesque received mixed to positive reviews from critics and audiences, earning a 64% approval rating on Rotten Tomatoes.