Scarcely anything is known of his life. His poetical efforts were not generally appreciated, although he received encouragement from his younger contemporary Plato (Plutarch, Lysander, 18).
His chief works were: an epic Thebais, an account of the expedition of the Seven against Thebes and the war of the Epigoni; and an elegiac poem Lyde, so called from the poet's mistress, for whose death he endeavoured to find consolation telling stories from mythology of heroic disasters (Plutarch, Consul, ad Apoll. 9; Athenaeus xiii. 597).
Antimachus was the founder of "learned" epic poetry, and the forerunner of the Alexandrian school, whose critics allotted him the next place to Homer. He also prepared a critical recension of the Homeric poems.
He is to be distinguished from Antimachus of Teos, a much earlier poet to whom the lost Cyclic epic Epigoni was apparently ascribed (though the attribution may result from confusion).