| Director | Dario Argento |
|---|---|
| Budget | $14 million |
| Box office | $32,655 |
Turin, Italy: French flight attendant Linda and Italian-American detective Enzo Avolfi team up to find Linda's younger sister Celine. Celine, a model, has been abducted by a serial killer. Known only as "Yellow" ("Giallo" in Italian), he kidnaps beautiful foreign women in his unlicensed taxi cab. After drugging them, the killer proceeds to mutilate and finally murder them. He photographs his deeds so that the photos may grant him personal sexual gratification.
Enzo receives a phone call from a fellow officer, who finds the body of an Asian woman outside a church near a fountain. They find out she's still alive, and starts to speak in Japanese. Enzo and Linda start to look for a translator, who tells them that the girl was praying Buddha and then repeated "yellow." They visit the morgue, where Linda realizes that the killer's face could be yellow, and the coroner tells Enzo that yellow skin is a symptom of liver disease, so the killer might be on the waiting list for a new liver.
They go to the hospital and find Giallo, but he escapes. Enzo finds out his name is Flavio Volpe and gets his address. Giallo starts to torture Celine by cutting one of her fingers when she starts to bad-mouth him. Enzo breaks into Giallo's apartment but finds it empty and full of torture devices.
Enzo tells Linda why he became a policeman: long ago, Enzo, who was 10, witnessed his mother being murdered by a local butcher, to whom she owed money. Enzo kills the butcher in his own shop five years later, while Inspector Mori knows why he did it. Mori took him in as if he were his own son. Enzo had kept the knife he used to kill the butcher as a reminder of how he became a cop. Enzo also tells Linda that Giallo might be a pattern killer who hates beautiful women due to his deformity.
Throughout the film, Enzo and Linda find more victims and clues about who the killer is and why he tortures them. An origin story shows that Giallo's mother was a prostitute who gave her son up for adoption at a church, where orphaned kids started to bully him. Celine tries to escape from Giallo but gets captured. Just when he is about to strangle her, Celine tells him she's rich and will reward him with money.
Giallo breaks into Linda's apartment and demands a ransom for the safe return of Celine. The film ends with Enzo and Giallo having a shootout in a hotel. Giallo tries to escape but falls from a skylight to the lobby floor, dying instantly. The police searched his apartment for Celine but could not find her. They also try finding her at an abandoned gas factory where Giallo brings his victims.
Linda starts to blame Enzo for killing her sister, as well as calling him selfish and inhumane, because Giallo was going to tell her the location of where her sister is. Enzo tries to convince Linda that Giallo as a killer could not be trusted. After telling her this, he walks away while Linda continues to berate him. By chance, while patrolling a car park, a policeman hears Celine as she tries to gain attention, tied up and gagged in the trunk of Giallo's car.