After reading a promising screenplay by an accountant named Afrim, “one lung” film producer Robert “Bobby” Bowfinger rallies his friends and associates for a meeting at his decrepit office. The following morning, Afrim explains the concept for his science-fiction alien invasion story, Chubby Rain, to actors Carol and Slater, who are desperate for work and accept Bowfinger’s promise that production will move ahead. Later, Bowfinger stops by a swanky Beverly Hills, California, restaurant and feigns a mobile phone conversation to attract the interest of major studio producer Jerry Renfro, who is seated nearby. Renfro glances at the Chubby Rain script and promises Bowfinger a deal if he can sign internationally-renowned action star, Kit Ramsey. Screenplay in hand, Bowfinger sneaks into Kit’s estate and pretends to be a fellow member of a religious organization called MindHead, but Kit realizes he is an imposter and throws him out. Back at his production office, Bowfinger tells Carol, Slater, and Afrim that Kit Ramsey has agreed to do the project. He confesses his lie to his cameraman friend, Dave, but reveals he has devised a plan to include Kit in the picture by filming him without his knowledge. Insisting he can shoot Chubby Rain on his life savings of $2,184, Bowfinger begins casting. At Slater’s insistence, he hires Daisy, a naive aspiring actress recently arrived from Ohio. With illegal Mexican immigrants working as the crew, Dave borrows camera equipment from his job at a film studio, and uses it to film Daisy chasing Kit’s limousine as he leaves his house. Bowfinger maintains the charade by telling the other actors that Kit is a “Method” performer who wishes to remain in character by keeping the camera out of sight. When Carol shouts her lines at Kit on a restaurant patio, the actor becomes fearful that he is being stalked by aliens and goes to see his MindHead mentor, Terry Stricter, for counseling. Bowfinger and his crew secretly record Kit leaving the parking garage and create the illusion he is being followed, causing Kit to flee in panic. Later, Bowfinger constructs a chase scene by editing Kit’s reactions with separately-shot footage of Carol. When Carol independently approaches Kit to congratulate him on the scene, Kit has a nervous breakdown and agrees to spend a few days at MindHead’s celebrity retreat. Unable to locate their star, Bowfinger hires a nerdy look-alike named Jiffrinson to serve as Kit’s double and run errands for the crew. After cutting his hair like Kit’s, “Jiff” films a dangerous scene running across a busy freeway. Desperate for more screen time, Daisy has Afrim write added love scenes between her and Kit, then asks Bowfinger if they can meet to discuss them. When Bowfinger invites her over for dinner, Daisy seduces him. Bowfinger steals her credit card to buy professional equipment, and Dave "borrows" Jerry Renfro’s valuable vintage car to use in the film. Following a tip from Carol, Bowfinger tracks Kit’s location to a Beverly Hills boutique and resumes production. Slater and Daisy approach Kit and act out a scene featuring dialogue about an alien attack. His fears renewed, Kit escapes. While the crew eats lunch, Jiff casually mentions he resembles Kit because they are brothers. He earnestly thanks his co-workers for not exploiting him, leaving Bowfinger feeling guilty. When Bowfinger learns that Daisy had sex with Jiff in the production van, he tries to end his relationship with her, but she convinces him to reconsider. Meanwhile, a studio security guard notices Dave returning unauthorized equipment marked with Kit’s name and alerts MindHead that something is amiss. Following Kit’s car, the film crew shoots a high-speed chase sequence. Afrim and another actor arrive dressed as police officers, and Afrim uses special effects makeup to appear as if his body is melting. Daisy drives onto the scene in Renfro’s stolen car, and convinces Kit to get in and play along. The crew rush ahead of them and set up their equipment in the security office of the Griffith Park Observatory. Pointing the camera at the wall of security monitors, Bowfinger records Daisy and Kit’s actions as they run to the roof and encounter Carol. Daisy stages the murder of Carol’s alien character, which Kit believes to be real, and leads him to the top of the dome. There, she urges Kit to shout the film’s tagline, “Gotcha suckers!” but Kit’s MindHead mentor, Terry Stricter, arrives by helicopter and shuts down the production. Sometime later, the disappointed cast and crew review the footage they collected, which includes a shot of Kit exposing himself to the cheerleaders of the Los Angeles Lakers basketball team. Using the tape as blackmail, they gain Terry Stricter’s permission to release the film. Following the surprisingly successful premiere of Chubby Rain, Bowfinger receives an offer to direct a picture in Taiwan featuring Jiff Ramsey. There, the crew reunites to produce a Kung-Fu picture titled, Fake Purse Ninjas, in which Bowfinger also has a starring role.