Mel Coplin and his wife, Nancy, live in New York, near Mel's neurotic, Jewish, adoptive parents, Ed and Pearl Coplin. Mel and Nancy have just had their first child, and Mel won't decide on a name for their son until he can discover the identity of his biological parents. After an adoption agency employee locates his biological mother's name in a database, Mel decides to meet her personally.
Tina, the sexy but highly incompetent adoption agency employee, decides to accompany Mel, Nancy, and the newborn on a trip to San Diego to meet Mel's biological mother. The trip, of course, does not go as planned, and ends up becoming a tour of the United States.
First, Mel is introduced to Valerie, a blond Scandinavian woman with Confederate roots whose twin daughters are at least six inches taller than Mel. They quickly realize that Valerie is not Mel's biological mother, and Tina scrambles to get the correct information from the agency database. Meanwhile, Nancy becomes jealous as Tina and Mel begin to flirt.
Next, the group heads to Battle Creek, Michigan with the hope of meeting the man whose name appears as the person who delivered infant Mel to the adoption agency. The man, Fritz Boudreau, turns out to be a trucker with a violent streak. However, when he discovers that Mel might be his son, he becomes instantly friendly and lets Mel drive his semi-trailer truck, which Mel immediately crashes into a Post Office building.
This leads to a run-in with two ATF agents, Tony and Paul, who are gay and in a relationship with each other. It is discovered that Tony and Nancy went to high school together. Charges are dismissed, and Fritz Boudreau tells Mel that he is not Mel's father, but only handled Mel's adoption because Mel's biological parents were indisposed. Tina locates the current address of Mel's biological parents, which turns out to be in rural New Mexico. Tony and Paul surprise everyone by deciding to tag along on the trip.
While Mel and Tina become close, Nancy finds herself flirting with Tony, who returns the compliment, causing friction. The trip through rural New Mexico is fraught with more problems. At last the whole crowd descends on the front porch of Mel's true biological parents, Richard and Mary Schlichting. They are asked to stay the night. While Richard and Mary are more than welcoming, Mel's biological brother Lonnie is overly rude and jealous. It is during dinner that Mel discovers that Richard and Mary had to let Mel be adopted because they were in jail for making and distributing LSD in the late 1960s. Not only that, but Richard and Mary continue to manufacture LSD, as becomes apparent when Lonnie, in an attempt to dose Mel with acid at dinner, accidentally doses Paul, the ATF agent.
In his drugged state Paul tries to arrest Richard and Mary but Lonnie knocks him out with a frying pan. They attempt to escape and decide to take Mel's car, hiding their supply of acid in the trunk. Mel's adoptive parents arrive but then change their minds and decide to leave, taking the wrong car. When they change their minds again and make a blind U-turn, the two families crash. Mel's adoptive parents are arrested while his biological parents escape to Mexico.
Not realizing what has happened Mel recounts the stories from dinner to Nancy and they agree to name the baby Garcia. The next day Paul explains the situation and is able to get Mel's parents released, and they are happy and reassured to hear Mel call them his parents. A montage of their relationships continues over the credits. They all still have their troubles but Mel and Nancy are happy together.Ben Stiller as Mel Coplin
Patricia Arquette as Nancy Coplin
Téa Leoni as Tina Kalb
Mary Tyler Moore as Pearl Coplin
George Segal as Ed Coplin
Alan Alda as Richard Schlichting
Lily Tomlin as Mary Schlichting
Richard Jenkins as Paul Harmon
Josh Brolin as Tony Kent
Celia Weston as Valerie Swaney
Glenn Fitzgerald as Lonnie Schlichting
Beth Ostrosky as Jane
David Patrick Kelly as Fritz Boudreau
Nadia Dajani as Jill
Rotten Tomatoes rated the film as "Certified Fresh" giving it an 86% based on 51 reviews.
A soundtrack album was released on Geffen Records that includes the following tracks
- "Anything But Love" (Dr. John and Angela McCluskey)
- "Somebody Else's Body" (Urge Overkill)
- "Outasight" (G. Love and The Philly Cartel)
- "You're Not a Slut" (Ben Stiller And Celia Weston)
- "Camel Walk" (Southern Culture on the Skids)
- Lend Me Your Comb" (Carl Perkins)
- "Acid Propaganda" (Lily Tomlin / Alan Alda / Ben Stiller)
- "You Part the Waters" (Cake)
- "Lonnie Cooks Quali" (Glen Fitzgerald)
- "Red Beans N' Reverb" (Southern Culture on the Skids)
- "Flirting with Disaster" (Dr. John and Angela McCluskey)
- "Hypospadia" (Patricia Arquette / Josh Boslin / Tea Leoni / Ben Stiller)
- "Melodie D'Amour (Cha, Cha, Cha D'Amour)" (Dean Martin)
- "For Duty and Humanity" (Inch)
- "The Flirting Suit" (Stephen Endelman)