The Bouvier-Sauvages, a large aristocratic family, meet the much more modest Martin family when their children's wedding is announced. For the occasion, the future bride and groom offer their parents DNA tests, which will reveal their true origins. The results are totally unexpected and will make the effect of a bomb.
| Actor | Role |
|---|---|
 Christian ClavierFrédéric Bouvier-Sauvage | Frédéric Bouvier-Sauvage |
 Didier BourdonGérard Martin | Gérard Martin |
 Sylvie TestudNicole Martin | Nicole Martin |
 Marianne DenicourtCatherine Bouvier-Sauvage | Catherine Bouvier-Sauvage |
 Julien PestelFrançois Martin | François Martin |
 Chloé CoulloudAlice Bouvier-Sauvage | Alice Bouvier-Sauvage |
 Patrick PréjeanGérard Martin's father | Gérard Martin's father |
 Sophie FroissardMaria, housekeeper | Maria, housekeeper |
 Johann DionnetMr. Ribeiro, plumber | Mr. Ribeiro, plumber |
 Loïc RojouanConcession Man | Concession Man |
 Charline PaulHairdresser | Hairdresser |
 Philippe VieuxGendarme | Gendarme |
 Damien BellardEmbassy Counselor | Embassy Counselor |
 Laurent JolyGenealogist | Genealogist |
 Laura MüllerLaboratory technician | Laboratory technician |
 Sébastien BoissavitMercedes salesman | Mercedes salesman |
 Sophie OlsenA cousin (uncredited) | A cousin (uncredited) |