The play begins as Barabas, a Jewish merchant, waits for news of the safe return of his ships. When he has heard this good news, he then finds out that all Jews must give half of his wealth to enable the government pay tribute to the Turks. Barabas protests, and thus has all of his wealth confiscated and his house turned into a convent. Barabas vows revenge but wants some of his wealth back, so his daughter, Abigail, converts to Christianity, enters the convent and steals her father's gold out at night.
Barabas then plans to use his daughter's beauty and the way she has caught the eye of Lodowick, a friend of the governor, to achieve his revenge. Barabas makes both Lodowick and Mathias believe Abigail is promised to them, and then Barabas stirs up more animosity between these two men by sending a letter from one of them (supposedly) challenging the other to a duel. These two men then kill each other in this duel. The governer and the mother of Mathias vow revenge against Barabas, and Abigail finds out. In response to her grief, she enters the convent properly this time to escape her father. Barabas is so angry at this that he poisons some rice and sends it to the convent.
Abigail reveals her father's devilry to two priests, close to death herself, after the death of all the nuns, although she knows that the priests are unable to reveal this truth because it was said during confession. The priests approach Barabas, and he, becoming aware of their knowledge, distract them by pretending to convert and giving his wealth away. The two priests begin to fight over which church Barabas should join. Barabas kills one of the priests and frames the other for the crime.
In the final act, the crimes of Barabas are made public and he fakes his own death to try and escape, going to the Turkish leader and betraying his own town. After a successful Turkish invasion, Barabas is made governor. However, out of paranoia, Barabas tries to make a deal with the original governor, saying he will liberate the town and kill the Turkish leader for money. Barabas invites the Turkish leader to a feast, but when he arrives, the governor prevents him from killing him, and both watch as Barabas slowly dies in a cauldron that was to be used to kill the Turkish leader.