Andie Anderson (Kate Hudson) is a writer for a women's magazine called Composure as the "How to..." girl. She is bored and wishes she could write more about important things such as politics, economics, religion, poverty; stuff she actually cares about. After Andie's best friend Michelle (Kathryn Hahn) experiences yet another break-up, Andie is inspired to write a new article titled "How to Lose a Guy in 10 Days"; she will start dating a guy and eventually drive him away using only the "classic mistakes women make" in relationships.
At the same time, advertising executive Benjamin Barry (Matthew McConaughey) is striving for a pitch to advertise a new diamond campaign. When his boss questions Ben's knowledge about romance, Ben bets he could make any woman fall in love with him if he wanted to. His boss accepts the bet and confirms that if he can make any woman fall in love with him before the upcoming company ball, in just 10 days, he will allow Ben to head the advertising for the new diamond company. Ben's rival co-workers, Judy Spears (Michael Michele) and Judy Green (Shalom Harlow), who were at Composure magazine earlier in the day and are aware of Andie's new assignment, set Ben up to have him pick Andie as the girl to test his theory on.
Ben and Andie meet and soon their quests, neither revealing their true intentions. Andie works hard to drive Ben insane and make him break up with her in order to complete her article, but Ben continues to stick around in hopes of making her fall in love with him. Andie gets Ben knocked out in a movie theater by talking aloud while watching a chick flick, rapidly moves her things into his apartment, acts overly possessive and sensitive and clingy, ruins his boys' poker night for him and his friends, and takes him to a Celine Dion concert when he was under the assumption he was going to see a New York Knicks basketball game.
Ben stays with her despite everything, and after coming very close to breaking up they attend couples counseling, led by Andie's friend Michelle. They agree, as a solution to their "problems", to visit Ben's family in Staten Island for the weekend. While holidaying together, Ben and Andie begin to form a genuine bond, and upon arriving home Ben even refers to Andie as his girlfriend. Andie then tries to explain to boss Lana (Bebe Neuwirth) that she cannot continue writing and publishing this article as she has "really got to know this guy", but Lana remains insistent upon it. Around the same time, Andie and Ben go to the company ball together where Ben's boss, Phillip (Robert Klein), meets Andie and tells Ben that he "met her, she loves you, you win".
Seeing Ben's good news, Judy and Judy are instantly envious and set about to ruin it for their co-worker. They tell his close colleagues, Tony (Adam Goldberg) and Thayer (Thomas Lennon), that Andie knew about the bet all along and was playing along to help Ben win. Tony and Thayer then rush to Andie's side and beg her to keep quiet, when they do not realize she is still blissfully unaware of the bet. Almost simultaneously, Lana, who is unaware of Ben's role in Andie's "How To" article, reveals Andie's true intentions to Ben. Upon learning of Ben's bet, Andie attempts to humiliate Ben in front of everyone at the party, and the pair argue on stage.
They go their separate ways before Ben is shown Andie's article and encouraged to read it. She explains in it how she "lost the one person she ever fell for", and when he hears she quit her job at Composure and is on her way to Washington, D.C. for an interview, he chases her taxi and stops her. Once he accuses her of running away, they reveal their true feelings for each other and the film ends with Ben instructing the taxi driver to return Andie's belongings to her home, and then they kiss.Kate Hudson as Andie AndersonMatthew McConaughey as Benjamin BarryKathryn Hahn as MichelleAnnie Parisse as JeannieAdam Goldberg as TonyThomas Lennon as ThayerMichael Michele as Judy SpearsShalom Harlow as Judy GreenRobert Klein as Phillip WarrenBebe Neuwirth as Lana JangMarvin Hamlisch as Himself (Cameo)
Gwyneth Paltrow was originally going to star as Andie Anderson but later pulled out before pre-production began, and Kate Hudson replaced her.
The yellow gown Kate Hudson wore in the movie was designed by celebrity designer Dina Bar-El. The necklace she wears with the yellow gown is called, in the film, the "Isadora Diamond" named after Isadora Duncan. The 80-carat yellow diamond in the necklace was designed by Harry Winston and is worth $6 million.
How to Lose a Guy in 10 Days received mixed reviews from critics. Rotten Tomatoes gave the film a rating of 42%, based on 161 reviews, with an average rating of 5/10. The site's critical consensus reads, "Matthew McConaughey and Kate Hudson are charming together, but they can't overcome How to Lose a Guy in 10 Days' silly premise and predictable script." Metacritic gave the film a score of 45 out of 100, based on 31 critics, indicating "mixed or average reviews".
The film was released on February 7, 2003 and earned $23,774,850 in its first weekend. Its final gross is $105,813,373 in the US and $71,558,068 overseas.