Shirlee Kenyon, a small-town dance instructor, spends too much time chatting with her clients about their problems, and is fired. Her unemployed boyfriend, Steve, is upset, and Shirlee suggests they move to Chicago, Illinois, where it might be easier to find work. Instead, Steve berates Shirlee and goes out drinking with his friends. Shirlee packs her clothes and sets out alone for Chicago. There, Shirlee stops to make a wish on a bridge. As she reaches into her wallet for a coin, several twenty dollar bills blow away. One lands on the other side of the ledge and Shirlee climbs over to retrieve it. Jack Russell, a reporter in a nearby building, sees Shirlee through his window, believes she is jumping, and rushes to save her. However, Jack’s “rescue” knocks her off the ledge. He grabs her arm and pulls her to safety, but the money flies away. He is surprised to learn she was not attempting suicide, and offers her money, but Shirlee refuses. She rents a cheap hotel room, then stops at a diner for breakfast. Noticing another customer, Janice, is upset, Shirlee learns that Janice is dating a workaholic who always breaks their dates. Shirlee advises Janice to “honk her own horn,” and get on with her life. They are interrupted by the arrival of Jack, the reporter, and Shirlee discovers he is Janice’s boyfriend. Janice takes Shirlee’s advice, declares she plans to date someone who values her, and leaves. Shirlee’s job search is fruitless until she answers an advertisement for a receptionist at a radio station. Although Shirlee has no experience, she commiserates with her interviewer, Ellen, over ex-boyfriends, and is hired. Meanwhile, station manager Alan Riegert promises his boss, Gene Perlman, that their new radio talk show host, Dr. Kendall, will boost ratings. Perlman only cares that she is a doctor, and not boring like Alan’s last hire. In the studio, the show’s producer and engineer are frantic that it is almost air time and Dr. Kendall has not arrived. Shirlee is on her break, sees their coffee machine, and stops to pour herself a cup. Although her last name is “Kenyon,” not Kendall, they assume she is the new host, and pressure her to answer the telephone. Shirlee’s natural inclination to chat serves her well, and she gives straight-forward, homespun advice, often suggesting people “honk” their own horn. Alan listens to the program while driving in traffic. He is horrified, speeds back to the office, and fires Shirlee. However, fans inundate the station with calls, so Alan offers to double her receptionist salary of $250 if she will return to host the show. Shirlee accepts the job, but refuses to sign the contract as “Dr. Kenyon.” Alan offers her $800 per week, and insists he will make up a great background for her. Shirlee is uncomfortable lying, but Alan claims she is a “doctor of the heart” and must not let her listeners down, so she signs. Alan learns more about Shirlee’s background, including her three marriages and divorces to the same man. He decides to decline interviews, and orders Shirley to remain silent about her past until he makes up something. The “Dr. Shirlee” show is a huge success. Alan purchases her a new wardrobe, and Gene Perlman gets her a pink Mercedes. When Jack sees a television news report about Shirlee’s show, he wonders how someone who was so desperate to retrieve twenty dollars is a successful doctor, and decides to investigate. Jack follows Alan and Shirlee to a cocktail party at an aquarium. While Alan talks to businessmen, Shirlee wanders the exhibit. Jack joins her and flirts as they discuss her show and his relationships. He asks Shirlee for a date, and she accepts. Later, they dine at a fancy restaurant, and Jack asks about her background. Their conversation is interrupted by Alan, who is also dining there. He wants to introduce Shirlee to television talk show host Zim Zimmerman. Despite refusing other interview requests, Alan is determined to get Shirlee on Zim’s successful show. Later, Jack drives Shirlee home and is surprised to find she lives in a “dive” hotel. Shirlee admits she likes Jack, and they kiss. Prior to the Zim Zimmerman show, Alan coaches Shirlee on her answers, but she refuses to lie. Alan insists Zim has promised to stick to pre-approved questions. However, Zim brings on another radio psychiatrist, Dr. David Erdman, who is stuffy and self-promoting. Zim asks the two doctors to respond to a caller who is upset about her husband’s affair. Dr. Erdman tells the woman to ignore the infidelity, insisting she does not hate her husband, but lacks self confidence. Shirlee angrily chides Dr. Erdman for blaming the woman for her husband’s cheating. Erdman notes he is an Ivy-league trained psychiatrist and questions Shirlee’s credentials. Declaring she was trained at “Screw U,” Shirlee encourages the woman to stand up for herself. The audience loves Shirlee and Alan is thrilled with the interview. However, Shirlee worries that she is not a trained doctor and might harm someone. On her next radio show, she receives a call from Sean, a “sober alcoholic” whose marriage is shaky because his wife still drinks. Shirlee advises Sean that if his wife refuses to stop drinking, he should leave her. After the show, Gene Perlman announces the network wants to take Shirlee’s show to the national level. When Perlman demands a promotional campaign featuring “Dr. Shirlee” at home, Alan quickly moves her into a fancy apartment. Meanwhile, Jack uses information gleaned on their date to find Shirlee’s hometown. He visits the dance studio where she worked, and pretends his name is “Mac” while talking to Steve at a local bar. Returning to Chicago, Jack takes Shirlee dancing and attempts to question her, but she tells him to relax and have fun. When they return to her new apartment, their kiss is interrupted by the arrival of Steve, announcing he recently learned of Shirlee’s success. Steve thinks he recognizes Jack, but cannot remember where they met. The two men dislike each other and when Steve punches Jack, Shirlee orders him to leave. Jack and Shirlee kiss, and he almost tells her the truth, but she asks him to wait until morning, and they make love. In the morning, he leaves a note asking her to meet him at the diner at noon, then quits his job at the newspaper rather than write about her. Steve remembers where he met Jack, and informs Shirlee that he is a reporter. She confronts Jack at the diner and they argue. He admits it started as a story, but he came to care about her and quit his job. They argue about lying, him to her and her to the world. Upset, she leaves and refuses to take his calls. When Alan escorts her to the station for her first coast-to-coast broadcast, they are confronted by the distraught wife of Sean, the sober alcoholic caller Shirlee previously advised. Sean left her and took their kids. Shirlee is surprised because Sean said they did not have children. The wife insists people do not always tell the truth, and Shirlee is giving advice to people she does not know. Shirlee is upset, and as her new show starts, she apologizes and admits she lied. She reveals she is not a doctor, and claims she is not qualified to give advice. She appeals to Sean to make his own decisions and not let anyone else tell him what to do. She thanks her audience for listening and leaves. Gene takes over the show, receiving calls from Shirlee’s numerous fans who want to support her by “honking their horns” at midnight. Jack hears the broadcast and searches for Shirlee. Stopping to make a call at his former office, he sees her on the bridge. He races to join her, and tells her that she did help her listeners. Sean called after Shirlee left, and stated that he had already planned to leave his wife, and was appreciative of Shirlee’s support. Jack declares that her fans do not care whether Shirlee is a doctor, and as the clock turns to midnight, car horns across Chicago honk for her. Jack kisses her, and nearby police officers think he is attempting to throw her off the bridge until they recognize Dr. Shirlee and honk in support. She smiles, and insists she is just Shirlee now.