Loosely based on the mythological story of Atalanta, the opera is set in legendary times of ancient Greece.

Act 1
King Meleagro of Aetolia has disguised himself as a shepherd, taking the pseudonym Tirsi, and is enjoying his life in the countryside away from the cares of state. He is very much in love with the huntress "Amarilli", whom he does not realise is the Princess Atalanta. He meets up with Aminta, a real shepherd, who is desperately in love with the shepherdess Irene, who however when she appears, does nothing but pour scorn on Aminta. He declares he is ready to die for his love but will always be faithful to her.

Nicandro, Irene's father and Meleagro's friend, tells Meleagro that Irene really loves Aminta too but she wants to be sure that he will be true to her.

Princess Atalanta of Arcadia now comes on to the scene. She too has taken another name, Amarilli, and has retreated to the country disguised as a huntress. Everyone prepares to go hunting, but Atalanta will not permit Meleagro to remain by her side during the hunt, although she is really in love with him. When a wild boar comes running out of the woods, Aminta tries to throw himself into its path, so distraught is he by Irene's seeming rejection, but the others prevent him. Atalanta kills the boar and rejoices in her triumph.

Act 2
Everyone is celebrating Atalanta's triumph in killing the wild boar, but she herself is feeling sad because she is in love with "Tirsi". However she, a princess in disguise, cannot marry the simple shepherd "Tirsi", who she does not realise is really King Meleagro, in disguise himself. Meleagro overhears her musing on this unfortunate state of affairs and tries to make his identity known to her but he is painfully shy and so is she and so they do not manage to clear things up. Irene pretends to be in love with Meleagro, but she is only trying to torment Aminta further. Meleagro gives Irene a ribbon and asks her to give it to Atalanta and tell her how much he loves her.

Irene flaunts the ribbon Meleagro has given her to Aminta, pretending that she is really in love with Meleagro. Aminta protests against her cruelty. Atalanta gives Aminta an arrow which she asks him to present to Meleagro without mentioning her name. Meleagro knows she is really in love with him and is quite cheerful, but Atalanta feels that her duty will prevent her from ever confessing her love for him.

Act 3
Irene presents Atalanta with the ribbon Meleagro gave her. Atalanta is touched and sends word to Meleagro that he can learn all about her through Aminta.

Irene then encounters Aminta, who decides to give her some of her own medicine by flaunting the arrow Atalanta gave to him to give to Meleagro. Aminta says Atalanta gave the arrow to him because she is madly in love with him and he loves her too. Irene is furious and Meleagro, who has been watching and listening to this unobserved, is in despair. Irene confesses she has been in love with Aminta all along; Meleagro, left by himself and exhausted from all this emotional turmoil, falls asleep.

Atalanta enters, pondering over the strange coincidence that the ribbon sent to her by the shepherd "Tirsi" looks like the ribbon belonging to King Meleagro. Meleagro wakes up and Atalanta can restrain herself no more; she admits she loves him and they embrace.

Nicandro, Irene and Aminta enter; Irene and Aminta have sorted everything out and admit they love each other. Nicandro tells the shepherd "Tirsi" that the huntress "Amarilli" is really Princess Atalanta and Atalanta that "Tirsi" is really King Meleagro. There is now nothing to stop their marriage and both couples are joyous.

The heavens part and Mercury, messenger from Jove himself, descends on a cloud surrounded by cupids and the Graces. Mercury brings Jove's blessings on the royal couple, assuring them of personal happiness and the love of their people. The work ends with general rejoicings, celebrations, and a display of fireworks.