Jack Noah (Dreyfuss) is an actor filming in the small, fictional South American country of Parador when Alfonse Simms, the dictatorial president of Parador, suddenly dies of a heart attack. Not wanting to lose his position in power, the president's right-hand man, Roberto Strausmann (Julia) forces Jack to take the 'role of a lifetime' - that of the dead president, as the two men look so much alike. Jack accepts, eventually winning over the people and even the dead president's mistress (Braga). However, it isn't long before Jack needs to find a way to get out while keeping Roberto out of the loop.
This film contains examples of:
- Banana Republic: Parador is your typical backwards, authoritarian-ruled tropical country.
- The Cameo: Sammy Davis Jr. appears animating a holiday in Parador.
- Celebrity Impersonator: Basically the entire premise. A stage actor is recruited to portray a recently deceased dictator of a Latin American Banana Republic.
- Commissar Cap: One is part of the regalia of Paradorian President-For-Life Alphonse Simms, though it's wore with a jaunty tilt that deflates its impressiveness.
- Dead Person Impersonation: American actor Jack Noah hired/forced to impersonate the recently-deceased dictator of a Banana Republic.
- Emergency Impersonation: Jack gets coerced into pretending to be Parador's dictator (whom he resembles and was already good at impersonating) when the latter unexpectedly dies.
- Evil Chancellor: Roberto Strausmann, the chancellor of the deceased Alfonse Simms, is the one who came up with the plan to force Jack to take over as Simms so as to not lose his power.
- Latino Is Brown: Subverted, as Parador's history of being dominated by various foreign powers has led to a dictator named Alphonse Simms and his secret police chief Roberto Strausman (Raul Julia in pale makeup and a blonde wig). Truth in Television for many Latin American countries.
- Ms. Fanservice: Sônia Braga at her hottest.
- No Celebrities Were Harmed: While a Generalissimo dictator ruling over a Latin American Banana Republic is generic enough, in this movie's case, having a dictator who subverts Latino Is Brown to the point of having a not-at-all-Hispanic-sounding name like Alphonse Simms calls to mind some real life dictators like Augusto Pinochet (Chile) and Alfredo Stroessner (Paraguay).
- To the Tune of...: As the new president, Jack changes the national anthem to "Parador, te amo" ("I love you, Parador"), which goes to the tune of "Bésame Mucho". Sammy Davis, Jr. sings it. The previous Paradorian national anthem ("O Parador") is sung to the tune of "O Christmas Tree".
- Waxing Lyrical: During a scene where Jack has to address the crowd as the Paradorian President, he ad-libs his lines and uses the lyrics of "The Impossible Dream" from Man of La Mancha.