Caro's most important work was his translation of the Aeneid. He is also the author of poems, sonnets, and a comedy called Gli Straccioni. His work also includes two clever jeux d'esprit: La Fichelde, in praise of figs, and a eulogy of the big nose of Leoni Ancona, a local figure. His poetry is noted for the freedom and grace of its versification, so that many claim that he brought verso sciolto to its highest form in Italy. Caro also composed prose, including translations of Aristotle, Cyprian, and Gregory Nazianzen. Letters he wrote, both in his own name and on behalf of the cardinals Farnese, are considered remarkable for both the baseness they display and for their euphemistic polish and elegance.
Caro's fame was diminished because of the virulence with which he attacked Lodovico Castelvetro in one of his canzoni, and by his meanness for denouncing him to the Church for translating some of the writings of Philipp Melanchthon, and associate of Martin Luther.
He died in Rome in 1566. He is buried in the church of San Lorenzo in Damaso.