Ermione tells Cleone that her love for Pirro has turned to hate. Oreste declares his love for Ermione, but she rejects him (Duet: "Amarti?" / "I? Love you?"). Pirro arrives with the grandees and his retinue, who announce that he has changed his mind and will return to Ermione (Chorus: "Alfin l'Eroe da forte" / "At last, the resolute hero"). Pirro then tells Oreste, to the astonishment of everyone, that he will, after all, hand over Astianatte to him. (Ermione, then the others and Pirro: "Sperar, poss'io?" ... "A me Astianatte" / "Should I, can I, hope?" ... "Bring Astianatte here") As the guards prepare to do so, Andromaca pleads with Pirro to give her time to think. Ermione is furious, and Pirro again rejects her. Andromaca vows to commit suicide if she is compelled to marry Pirro, while Pilade urges Oreste to leave with him. The Act ends in general consternation.