Andie Anderson (Kate Hudson) is a journalist, who works for a magazine called Composure as the "How to..." woman. She is bored and wishes she could write more about important things, such as politics, economics, religion, poverty, and so on. She soon finds herself writing an article called "How to Lose a Guy in 10 Days". Andie tells her boss that, to write more freely and creatively, she will date a man and do all the wrong things women tend to do in relationships, and record her experiences for the article. At the same time, advertising executive Benjamin Barry (Matthew McConaughey) tells his boss that he can make any woman fall in love with him in just ten days. To prove it, he will find a woman and bring her to the upcoming company ball as his date. If he succeeds, he gets to be in charge of the advertising for the new diamond company account otherwise headed by his boss. Ben's rival co-workers, Judy Spears and Judy Green, who were at Composure Magazine earlier and are aware of Andie's new assignment, conspire to have Andie and Ben meet that night and start their quests. Neither Andie nor Ben reveal their true intentions. Andie puts Ben through various experiences to make him quickly break up with her, but Ben sticks around in order to make her fall in love with him. Andie acts in a possessive way, interferes with Ben's Poker night, and takes him to a Celine Dion concert instead of a New York Knicks basketball game. Ben stays with her despite everything and both reveal their true motives at the end, but their initial desires have changed.