Alex "Hitch" Hitchens is a professional "date doctor" who coaches other men in the art of wooing women, with the main focus of having genuine long-term relationships. He is very successful at what he does.
While coaching one of his clients, Albert Brennaman—who is smitten with a client of his investment firm, celebrity Allegra Cole—Hitch finds himself falling for Sara Melas, a gossip columnist and cynical workaholic. While Albert and Allegra's relationship progresses, Hitch has difficulty connecting with Sara, none of his romantic methods work on her. Throughout the entire process, he keeps his career secret, claiming to be a generic "consultant".
Hitch meets with Vance Munson, a shallow misogynist attempting to get Hitch to help him land a one-night stand with Casey Sedgewick, Sara's coworker and best friend. Although Hitch refuses to help, Vance smugly misleads her into believing that he has used Hitch's services. After finding out Hitch's true identity, Sara publishes an exposé, causing Albert to vandalize a newsstand in rage and get arrested, Allegra to break up with Albert, and Hitch's reputation to suffer.
At a speed dating event that Hitch sneaks into, Sara and Casey confront him and cite Vance as their source. Hitch explains that not only did he refuse to work with him but also the extent to which women must protect themselves from men like Vance unintentionally makes establishing genuine relationships with good men difficult enough to create a demand for Hitch's services.
After receiving some criticism from Albert about treating love as a job instead of an actually legitimate feeling, Hitch then tries to salvage Albert and Allegra's relationship by confronting her. When she mentions how Albert's quirks won her over, Hitch realizes he does not really do anything significant besides giving his clients confidence and allowing them to get the attention of the women they love. And most of his customers, particularly Albert, really were successful by just being themselves. Allegra reconciles with Albert, and Hitch and Sara repair their relationship.
Albert and Allegra get married. During the reception, Casey gives the Heimlich maneuver to an elderly woman who was choking on a grape, which endears her to the woman's attractive grandson (it is revealed the elderly woman was working with Hitch). A dance party then begins with Albert, Allegra, Sara, and Hitch, which ends with Albert accidentally ripping his pants open to do the splits.
