Giovanni, recently returned to Parma from university in Bologna, has developed an incestuous passion for his sister Annabella and the play opens with his discussing this ethical problem with Friar Bonaventura. Bonaventura tries to convince Giovanni that his desires are evil despite Giovanni's passionate reasoning and eventually persuades him to try to rid himself of his feelings through repentance.
Annabella, meanwhile, is being approached by a number of suitors including Bergetto, Grimaldi, and Soranzo. She is not interested in any of them, however. Giovanni finally tells her how he feels (obviously having failed in his attempts to repent) and finally wins her over. Annabella's tutoress Putana (literally, "Whore") encourages the relationship. The siblings consummate their relationship.
Hippolita, a past lover of Soranzo, verbally attacks him, furious with him for letting her send her husband Richardetto on a dangerous journey she believed would result in his death so that they could be together, then declining his vows and abandoning her. Soranzo leaves and his servant Vasques promises to help Hippolita get revenge on Soranzo, and the pair agree to marry after they murder him.
However, Richardetto is not dead but also in Parma with his niece Philotis. Richardetto is also desperate for revenge against Soranzo, and convinces Grimaldi that to win Annabella, he should stab Soranzo with a poisoned sword. Unfortunately, Bergetto and Philotis, now betrothed, are planning to marry secretly in the place Richardetto orders Grimaldi to wait. Grimaldi mistakenly stabs and kills Bergetto instead, leaving Philotis, Poggio, and Donado (Bergetto's uncle) distraught.
Annabella resigns herself to marrying Soranzo, knowing she has to marry someone other than her brother. She subsequently falls ill and it is revealed that she is pregnant. Friar Bonaventura then convinces her to marry Soranzo before her pregnancy becomes apparent.
Meanwhile, Donado and Florio go to the cardinal's house, where Grimaldi has been in hiding, to beg for justice. The cardinal refuses due to Grimaldi's high status and instead sends him back to Rome. Florio tells Donado to wait for God to bring them justice.
Annabella and Soranzo are married soon after, and their ceremony includes masque dancers, one of whom reveals herself to be Hippolita. She claims to be willing to drink a toast with Soranzo, and the two raise their glasses and drink, on which note she explains that her plan was to poison his wine. Vasques comes forward and reveals that he was always loyal to his master, and in fact he poisoned Hippolita. She dies spouting insults and damning prophecies to the newlyweds. Seeing the effects of anger and revenge, Richardetto abandons his plans and sends Philotis off to a convent to save her soul.
When Soranzo discovers Annabella's pregnancy, the two argue until Annabella realises that Soranzo truly did love her and finds herself consumed with guilt. She is confined to her room by her husband, who plots with Vasques to avenge himself against his cheating wife and her unknown lover. On Soranzo's exit, Putana comes onto the stage and Vasques pretends to befriend her to gain the name of Annabella's baby's father. Once Putana reveals that it's Giovanni, Vasques has bandits tie Putana up and put out her eyes as punishment for the terrible acts she has willingly overseen and encouraged.
In her room, Annabella writes a letter to her brother in her own blood, warning him that Soranzo knows and will soon seek revenge. The friar delivers the letter, but Giovanni is too arrogant to believe he can be harmed and ignores advice to decline the invitation to Soranzo's birthday feast. The friar subsequently flees Parma to avoid further involvement in Giovanni's downfall.
On the day of the feast, Giovanni visits Annabella in her room, and after talking with her, stabs her during a kiss. He then enters the feast, at which all remaining characters are present, wielding a dagger on which his sister's heart is skewered and tells everyone of the incestuous affair. Florio dies immediately from shock. Soranzo attacks Giovanni verbally, but Giovanni stabs and kills him. Vasques intervenes, wounding Giovanni before ordering the bandits to finish the job.
Following the massacre, the cardinal orders Putana to be burnt at the stake, Vasques to be banished, and the church to seize all the wealth and property belonging to the dead. Richardetto finally reveals his true identity to Donado and the play ends with the cardinal saying of Annabella "who could not say, 'Tis pity she's a whore?"
Soranzo – A nobleman (Annabella's suitor and eventual husband)
Florio – A citizen of Parma, and father of Annabella and Giovanni
Donado – A citizen of Parma, and uncle of Bergetto
Grimaldi – A Roman gentleman (Annabella's suitor)
Giovanni – Son of Florio (his name is pronounced with four syllables)
Bergetto – Nephew of Donado (Annabella's suitor and then Philotis's fiancé/suitor)
Richardetto – Hippolita's husband, disguised as a physician, also Philotis' uncle
Vasques – Loyal servant to Soranzo
Poggio – Servant to Bergetto
Banditti – Outlaws, a criminal mob
Annabella – Daughter of Florio
Hippolita – Wife of Richardetto (Soranzo's former paramour)
Philotis – Niece of Richardetto (becomes Bergetto's fiancée)
Putana – Tutoress of Annabella; her name derives from the Italian word for "whore", puttana.
The play's open treatment of the subject of incest made it one of the most controversial works in English literature. The play was entirely omitted from an 1831 collection of Ford's plays; its title has often been changed to something euphemistic such as Giovanni and Annabella or 'Tis Pity or The Brother and Sister. Indeed, until well into the twentieth century, critics were usually harsh in their condemnations of the play; the subject matter offended them, as did Ford's failure to condemn his protagonist. Critic Mark Stavig wrote, "Instead of stressing the villainy, Ford portrays Giovanni as a talented, virtuous, and noble man who is overcome by a tumultuous, unavoidable passion that brings about his destruction".
However, since the mid-twentieth century, scholars and critics have generally shown more appreciation of the complexities and ambiguities of the work, though the treatment of the main subject still remains "unsettling", in the words of Michael Billington, reviewing the 2014 production for The Guardian, because Ford refuses "to either condone or condemn incest: he simply presents it as an unstoppable force."
In 2011, Jonathan Munby directed a "Tarantino-esque" production of the play set in 1960s Italy, staged at the West Yorkshire Playhouse in Leeds from 7 to 28 May. Featuring an image of Christ and the Virgin Mary, the publicity poster for the play caused controversy before it even opened, and was replaced after a letter of complaint from the Roman Catholic Bishop of Leeds. In the lead roles, Damien Molony as Giovanni and Sarah Vickers as Annabella received praise for their performances.
Filmed for BBC Two by director Roland Joffé under its original title, and transmitted on 7 May 1980. Production starred Kenneth Cranham (as Giovanni) and Cherie Lunghi (as Annabella), and used an uned text while transferring the setting visually to eighteenth century England.