In 1965, Airman Second Class Adrian Cronauer arrives in Saigon to work as a DJ for Armed Forces Radio Service. He is met at the airport by Private Edward Garlick who drives him to the radio station, where his attitude and demeanor contrast sharply with those of many staff members. His show consists of reading strictly censored news and irreverent humor segments mixed with rock and roll music, which is frowned upon by his superiors, Second Lieutenant Steven Hauk and Sergeant Major Phillip Dickerson. Hauk adheres to strict Army guidelines in terms of humor and music programming while Dickerson, humorless and by-the-book, is generally abusive to all enlisted men. However, Brigadier General Taylor and the other DJs immediately take to Cronauer and his irreverent brand of comedy.
Cronauer follows Trinh, a Vietnamese girl, to an English class; after bribing the instructor to let him take over, Cronauer instructs the students in American slang and profanity. Once class is dismissed, he tries to talk to Trinh but is stopped by her brother Tuan; realizing the futility of pursuing her, Cronauer instead befriends Tuan and takes him to Jimmy Wah's, a local GI bar. Two racist soldiers, angered at Tuan's presence, initiate a confrontation that escalates into a brawl
Dickerson reprimands Cronauer for the incident, though his shows continue as normal, gaining popularity from many listeners while Dickerson and Hauk continue to dislike them. While relaxing in Jimmy Wah's one afternoon, Cronauer is rushed outside by Tuan, saying that Trinh wants to see him. A minute later, the building explodes, killing two soldiers and leaving Cronauer shaken. The cause of the explosion is determined to be a bomb; when Cronauer attempts to broadcast news of the explosion, Dickerson pronounces it as unofficial news, but Cronauer locks himself in the studio and reports it anyway. Dickerson is outraged and orders the broadcast cut off. Later, Dickerson and Hauk convince General Taylor to suspend Cronauer, and Hauk takes over Cronauer's broadcast, but his poor attempts at humor and selections of polka music lead to a flood of hate mail and phone calls demanding that Cronauer be reinstated.
Demoralized, Cronauer spends his time drinking and pursuing Trinh, only to be repeatedly rebuffed. At the radio station, General Taylor orders Hauk to reinstate Cronauer; Garlick delivers the news to Cronauer that he is back on the air, but Cronauer, still dejected, refuses to resume his broadcasts. Shortly afterward, Garlick is driving Cronauer and Tuan to their English class when their jeep is stopped on a congested street by a convoy of soldiers from the 1st Infantry Division heading for Nha Trang. Garlick introduces Cronauer to the troops who persuade him to do an impromptu "broadcast" before they go off to fight. Cronauer is moved by the soldiers' appreciation and is reminded why his broadcasts are important; he returns to work
Dickerson seizes an opportunity to permanently rid himself of Cronauer by approving his request to interview soldiers in the field and deliberately routing him through the hazardous Viet Cong-controlled highway to An Lộc. Cronauer and Garlick's Jeep hits a mine, and they are forced to hide in the jungle from VC patrols. Back in Saigon, Tuan is alarmed when Cronauer fails to show up for English class and learns from DJ Marty Dreiwitz that Cronauer also didn't turn up for his broadcast that morning. Tuan steals a van to search for Cronauer and Garlick. After Tuan finds them, the van breaks down and they flag down a Marine helicopter to fly them back to the city.
Back at the base, Dickerson tells Cronauer that he is off the air permanently. Tuan is revealed to be a VC operative known as "Phan Duc To" and is responsible for the bombing of Jimmy Wah's; Dickerson has arranged for Cronauer's honorable discharge. General Taylor regretfully informs Cronauer that he cannot help him this time since Cronauer's friendship with Tuan would damage the reputation of the US Army. After Cronauer leaves, Taylor informs Dickerson that he is transferring him to Guam, citing Dickerson's vindictive attitude toward Cronauer as the reason.
Cronauer searches for Tuan, decrying his actions against American soldiers. Emerging from the shadows, Tuan bitterly retorts that the US army massacred his village, thereby making the United States his enemy. Before disappearing again, Tuan comments that in spite of this, he still chose to save Cronauer's life at An Lộc, implying that he valued their friendship. On his way to the Tan Son Nhat Airport with Garlick, under MP escort, Cronauer sets up a quick softball game for the students from his English class and says goodbye to Trinh. He gives Garlick a taped farewell message for the troops and boards the plane; Garlick – taking Cronauer's place as DJ – plays the tape on the air the next morning, it begins with Cronauer saying "Goodbye, Vietnam!"
Robin Williams as Adrian Cronauer
Forest Whitaker as Private Edward Garlick
Tung Thanh Tran as Phan Duc To / Tuan
Chintara Sukapatana as Trinh
Bruno Kirby as Lieutenant Steven Hauk
Robert Wuhl as Marty Lee Dreiwitz
J. T. Walsh as Sergeant Major Phillip Dickerson
Noble Willingham as General Taylor
Richard Edson as Private Abersold
Richard Portnow as Dan "The Man" Levitan
Floyd Vivino as Eddie Kirk
Juney Smith as Phil McPherson
Củ Bà Nguyễn as Jimmy Wah
loosely based on the experiences of AFRS radio DJ Adrian Cronauer
The film is number 100 on the list of the "American Film Institute's 100 Funniest American Movies".