A satire of network television, the movie follows the adventures of an ambitious mailroom clerk, Steven Post (Russell) at the fictional struggling UBC (United Broadcasting Corporation) Network. Post discovers that a chimpanzee named Raffles, left in the care of his girlfriend Jennifer Scott (played by Heather North) by neighbors who moved to San Francisco, has the uncanny ability to choose which television programs will succeed or fail with audiences. While watching a program, Raffles blows a raspberry at shows he hates and claps his hands at shows he likes.
Post smuggles the chimp into the UBC building when various programs are being previewed for executives and watches as the chimp gives his vote from the projection room. The first program that receives Raffles’s approval is a movie named “Devil Dan”. Post tells the programming executives that “Devil Dan” will draw large audiences. The executives disagree and choose not to program the movie. To prove he’s got a sure-fire way of choosing hits, Post sneaks into UBC’s broadcast center to switch the reels. Executives are outraged when “Devil Dan” airs – but Post is proved right. The movie propels UBC to first place in the ratings war. Post successfully masks the chimp’s abilities as his own and rises to vice president of UBC, now the top-rated area network. However, this also creates suspicion and resentment among UBC executives, mainly because they believe Post is too young to merit the title of vice president. Their resentment reaches a breaking point at a television award ceremony where Steven Post receives the title of “Television’s Man of the Year” and the emcee mistakenly identifies Post as the president of UBC.
Fearing that Post’s seemingly miraculous abilities will make their own jobs unnecessary, network executives E. J. Crampton (Morgan) and Francis X. Wilbanks (Joe Flynn) attempt to discover his secret to success. One toady (Wally Cox) sees a bunch of bananas in Post’s apartment, which leads to a humorous scene where the executives are seen eating bananas as they believe an idea that a New Guinea tribe considered bananas to be brain food. The flunky also hears sounds coming from Post’s closet and believes he is holding a hostage, which serves to intensify the surveillance of Post and his new luxury apartment.
Using a spyglass to peer through his apartment window at night, the toady discovers the chimpanzee watching television with Post. Upon spying the chimp going to the refrigerator for a beer during the commercial break, the executives realize the chimpanzee’s true abilities.
Fearing the revelation that America’s favorite TV programs were being picked by a primate would spell the end of television, the executives decide to steal the chimpanzee and return it to the jungle.
Wilbanks and his chauffeur, Albert Mertons (Cox) venture out a narrow ledge in an attempt to snatch the chimp out of Post’s apartment in his absence. The plan goes awry and the duo become stranded on the ledge until the police, the fire department, and a Catholic priest arrive, mistaking their break in for a potential suicide.
As a last-ditch effort, the network offers Post $1,000,000 in exchange for the chimp, which he ultimately accepts. Jennifer becomes disenchanted with him when she finds out he sold her pet for money without her consent and breaks off their relationship. She also does not believe her chimpanzee should be released into the wild.
Meanwhile, executives from every studio and camera crews crowd a cargo plane soaring over the jungle, as they prepare to parachute the chimp into an unexplored section of the Amazon; but before arriving at the intended disembarkation point, the stubborn chimpanzee, not wanting to be sent into the wild, pulls a lever opening an emergency hatch which sucks all the executives out of the plane, causing them to parachute into the jungle instead. Albert Mertons, who is now more sympathetic to Jennifer’s feelings, reveals to Steven that the chimp outsmarted the executives and is now en route back to the United States.
Post uses this opportunity to refund the $1,000,000 for the chimp. Post comments that UBC is going to need the money now in order to fund a search party for Wilbanks and the other executives. Jennifer and Steven have not only rekindled their relationship, but are now married and set off on their honeymoon with the chimpanzee in tow as their pet. The final scenes shows the Posts on an expressway which pans out in a wide scene, while a radio announcement says that Post has just married and resigned his vice presidency of UBC, but many people are wishing him well in his future endeavors.