An ad man tours Mexico trying to cast a new radio show.

Dennis Lindsey, an advertising executive, goes to Mexico to find a singer for one of his client's radio shows. There, he hears the hot-tempered Carmelita Fuentes sing, and after several incendiary confrontations with Dennis, Carmelita accedes to her family's wishes and signs a singing contract with him. After Dennis promises to look after her welfare in New York and invites her to stay with him, his aunt Della and uncle Matt, she decides to steal him from his fiancée, Elizabeth Price. Although she is told to stay home on the day before her audition, Carmelita persuades Uncle Matt to take her to a baseball game and a wrestling match, where she loses her voice cheering on wrestler Mexican Pete. At the audition, Carmelita croaks out her songs, causing the sponsor to cancel the show. To cover for Uncle Matt, Carmelita tells Dennis that she was out with an unnamed man, prompting Dennis to threaten to send her back to Mexico. An angry Carmelita blames Mexican Pete for her bad luck, and the wrestler offers her a job in his nightclub as compensation. That night, Dennis entertains a divorced client, Tony Romano, at the club, and Romano, impressed by Carmelita's performance, hires her to advertise his perfume. As the night progresses, Elizabeth becomes jealous of Dennis' concern for Carmelita, while Dennis becomes jealous of Romano's attention to Carmelita. After the performance, Uncle Matt and Carmelita stay out all night at the bike races, and Carmelita leads Dennis to believe that she was out with Romano. While at a photo session at Romano's house, Carmelita calls Dennis and tells him that she is moving in with Romano. When Dennis decides to leave his wedding rehearsal to rescue Carmelita, Elizabeth breaks their engagement and Dennis rushes to Romano's house, scoops up Carmelita and carries her to the altar.