Jack Beauregard, an ageing gunman of the Old West, only wants to retire in peace and move to Europe. But a young gunfighter, known as "Nobody", who idolizes Beauregard, wants him to go out in a blaze of glory. So he arranges for Jack to face the 150-man gang known as The Wild Bunch and earn his place in history.

Arms dealer Yolaf Peterson aims to make a sale to guerilla Mongo, but the money is locked in a bank safe, the combination known only to Professor Xantos, a prisoner of the Americans. Yolaf agrees to free Xantos, accompanied by reluctant guerilla Basco, but a former business partner of Yolaf's- John 'The Wooden Hand', has other ideas.