In the comedy film 'A Song of Lisbon,' a young medical student in Portugal discovers that his wealthy aunt plans to leave him a large inheritance. In order to secure the money, he must deceive his aunt and others around him. Through a series of comedic mishaps, the student gets tangled in a web of lies and finds himself in hilarious situations.

Gracinda, a young laundry washer, lives with her godfather, "Uncle" Jacinto, and together they run a family business, doing the laundry for residents of Lisbon in their small village in the outskirts of that city (Canecas). Unfortunately, the business is not going very well, but that changes when Gracinda decides to go to the city to try to convince Chico, "Uncle" Jacinto's son, with whom she is in love, to return to the village and give new life to the business. The village is preparing for the annual festivities and a dispute erupts between "Uncle" Jacinto and his business rival , the widow Quiteria, when each of them invites different bands to play at the same time during the party and dances

Aninhas (Aida Lupo), a paralyzed girl, asks for a miracle from the saint of her devotion, Our Lady of Lourdes, at the chapel of Penha (Guimarães), but her prayer is not heard - She turns her devotion to the Blessed Virgin directly, and joins the multitude that goes on a pilgrimage to the village where, ten years before, the Virgin Mary is said to have appeared to three child sheepherders.