A golden bullet arrives in London, with 007's number engraved on it, the trademark of Francisco Scaramanga (Christopher Lee), an assassin who charges $1 million per victim. Bond (Roger Moore) is useless to M on his current assignment, searching for a missing solar-engineering expert, until this situation is resolved, so he goes to Beirut, where 002 was apparently shot by Scaramanga in 1969. With some difficulty, he obtains the bullet, and it's analysed by Q Branch. The gold/nickel content indicates it's probably been made by Lazar, a gunsmith based in Macao.

Bond persuades Lazar to tell him how Scaramanga collects his merchandise, and follows statuesque Miss Anders from a casino in Macao across to Hong Kong, where he meets with fellow agent Mary Goodnight (Britt Ekland), Further not so gentle persuasion of Anders gains the information that Scaramanga will be at the Bottoms Up club. He is - but Bond isn't the target. Gibson, the solar-engineering expert, is, and Scaramanga's midget henchman, Nick Nack, relieves the corpse of the solex, the key piece of the system. Bond is arrested by Lieutenant Hip and taken across Hong Kong Harbour, where he escapes on to the wreck of the Queen Elizabeth, which turns out to be a naval intelligence base. There, M assigns Goodnight to act as liaison between Bond and Hip while they investigate a new lead: Hai Fat, a wealthy Thai businessman, who could have afforded Scaramanga's fee.

Gambling that Hai Fat and Scaramanga won't have met, Bond, masquerading as the assassin, visits Hai Fat, and gets an invitation to dinner. Unfortunately the two are well acquainted and a trap is laid for Bond - he wakes in a karate school from which he escapes with Hip and his two karate kicking nieces' help. Hai Fat decides he will lie low, but Scaramanga kills Win. Miss Anders reveals that she sent the bullet to Bond: 007 is the only person Scaramanga fears. He even has a model of him in his Fun House. She agrees to get the solex and Bond will then deal with the assassin. They arrange to meet at a boxing tournament, but when Bond arrives she's already dead. Scaramanga warns Bond off, but Bond finds the solex and gets it to Goodnight, who then follows Nick Nack. Unfortunately, Scaramanga is following her and she is captured.

Bond gives chase, accompanied inadvertently by Sheriff J.W. Pepper, but Scaramanga's car becomes a plane and he flies off. Q's homing device in Goodnight's dress works, showing she's in Red Chinese waters. Unofficially, Bond strays into their territory, and arrives on Scaramanga's island. Scaramanga shows off his solar complex, complete with laser, with which he destroys Bond's plane. He then challenges Bond to a duel: his golden gun against Bond's Walther PPK. Bond accepts, and Nick Nack appears to help him. Eventually Bond replaces his own mannequin and shoots a very surprised Scaramanga. Goodnight, meanwhile, has dealt with Scaramanga's maintenance man, although, by tipping him in a vat of liquid helium, she's ensured that the place will explode. Bond retrieves the solex; he and Goodnight steal Scaramanga's junk and, after dealing with Nick Nack, who's stowed away, they take a slow boat from China.