Amyntas was the son of Andromenes. He was a Macedonian officer in the army of the legendary king of Macedonia, Alexander the Great. He was sent forward to receive the garrison of Sardis from Mithrenes, the commander of the Sardis army in 334 B.C. This garrison was surrendered to Alexander after the battle of the Granicus. In 332, he was appointed as the officer in charge of collecting taxes from the people of Macedonia, while Alexander was still in Egypt, planning his further advancement and conquest, after Gaza was seized. He came back with the levies in 331, when Alexander had conquered Susa.

Amyntas and his brothers Attalus and Simmias were close to Philotas, who was executed on the charges of treason and conspiracy against Alexander in 330 B.C. The three brothers were alleged to have played a part in the plot and were arrested. They were later proved innocent and acquitted after the reappearance of their fourth brother Polemon, who fled from the camp. Amyntas was killed by an arrow when he attacked a village.