Plot
Prologue:
In a frame story, Giotto (played by Pasolini) arrives in Naples to paint a mural. Ser Ciappelletto commits a murder and hides the body.
Andreuccio of Perugia:
In the first episode (based on Second day, fifth tale), Andreuccio of Perugia has come to Naples to buy horses. A prostitute plans to rob him of his money by inviting him to supper under the pretext that they are estranged siblings. Retiring for bed, Andreuccio undresses and uses a booby trap lavatory that drops him into a trough of excrement. He escapes and meets two thieves attempting the robbery of the lately-deceased Archbishop's jewels at a nearby church. Andreuccio agrees to climb into the lidded tomb and finds the Archbishops's prized ring, which he plots to keep for himself, but the thieves refuse to re-open the lid until he presents it. Later, more thieves enter with the same plan, encouraging their leader to enter the tomb because "dead men don't bite". Andreuccio bites his leg and the thieves run in terror while Andreuccio prances away with his new ring.
Ciappelletto, the Thief: In Naples, an old man is reading to an interested crowd a bawdy story (based on Ninth day, second tale). A nun, Isabetta, is having an affair with a man. When the other nuns discover this they rush to tell the Mother Superior, who they interrupt while she is having sex with a priest. She accidentally puts his underwear on her head, mistaking it for her veil. Isabetta points out the underwear and the nuns all realize the Mother Superior is guilty of the same sin. From that day forth, the nuns all get lovers.
While this story is being told, Ser Ciappelletto is picking pockets of men caught up in the story. He gives some money to a male child in exchange for sexual intercourse and the scene ends.
Masetto da Lamporecchio:
In the second episode (based on Third day, First tale), a young man, Masetto da Lamporecchio, is encouraged by a gardener to seek work at a local convent filled with many beautiful women. Masetto pretends to be deaf and mute to convince the pious Abbess to accept him in spite of his handsomeness. While tending the garden, two nuns decide to have sex with him because he cannot tell anyone, but the other sisters discover this and prove collectively insatiable. When the Abbess also commands him to have sex with her, he breaks his silence to protest that he cannot keep up with the nuns' demands. She declares his sudden speech a miracle from God, assuring him that he will be made a saint and that they will reach an arrangement to keep him satisfied.
Peronella:
In the third episode (based on Seventh day, second tale), Peronella cuckolds her dimwitted husband with her lover Giannello when he unexpectedly returns home. Peronella hides Giannello in a large pot, but her husband reveals he has found a buyer for the pot, so Peronella tells him that she has found a more generous buyer, explaining Giannello's presence. Giannello demands that the pot be cleaned before he buys it, so the husband climbs inside. Peronella points to different spots in the pot, instructing her husband in how to scrape the right spots while Giannello penetrates her.
Ser Ciappelletto of Prato:
In the fourth episode (based on First day, first tale), which begins in Prato, Ser Ciappelletto, a Neapolitan merchant, is sent to make a deal in Germany by his employer. Ciappelletto is sinful, blasphemous, and is homosexual, so his master sends him to Burgundy where he is unknown. He dines with two fellow Neapolitans who are usurers. That night, Ciappelletto has an ominous dream that he is being paraded around while wrapped in a burial shroud while around him friars and monks play volleyball with human skulls. He reaches Burgundy, where he falls into a serious illness in the usurers' house. They are outraged because if they turn him out they will be seen as bad hosts, but if his crimes are revealed in confession they will draw attention. Ciappelletto devises a plan to confess and calls a monk to tell him several lies and half-truths that make him seem very pure, while pretending to cringe over venial sins. In his dying breaths, he tells the monk that he has never had sex with a woman (leaving out that he is homosexual) which the monk sees as particularly chaste as he is handsome. The monk is amazed at Ciappelletto's virtue, and he is venerated as a saint. After the eulogy, many poor, disabled and sick people enter to touch his body in praise. The two Neapolitans look at each other in amazement that his plan worked.
Giotto's Pupil:
In a brief intermission (based on Sixth day, fifth tale), a pupil of the great painter Giotto is on his way to paint the Basilica of Santa Chiara with his companion Messer Forese da Rabatta. The cart he is in is stopped by the rain and they take cover with a toothless farmer nearby named Gennari who gives the passengers clothes. The pupil of Giotto and da Rabatta arrive at the church while dressed in these tattered outfits. The two begin painting the basilica's walls after watching passersby in a market for visual inspiration. He spots some market-goers who will serve as the actors in the next segment about Caterina and Ricciardo. The other stories of the film continue afterwards.
Caterina di Valbona and Riccardo:
In the fifth episode (based on Fifth day, fourth tale), the beautiful Caterina and wealthy Ricciardo fall in love while playing hide and seek. To give them an opportunity to have sex, she asks her parents whether she can sleep on the roof-terrace so she may hear the nightingale sing, where Ricciardo scales the wall. They have sex and fall asleep, but at dawn Caterina's father discovers them entwined. The mother begins to scream, but the father explains that the pair would be a good match as Ricciardo's family would improve their social standing and bring them money. The father wakes the pair and threatens Ricciardo's life, to which he promises to promptly wed Caterina; the father officiates the ceremony immediately and the parents leave them to consummate the marriage.
Elizabeth of Messina and Lorenzo the Sicilian:
In the sixth episode (based on Fourth day, Fifth tale), set in Messina, a girl, Elizabeth, attractive and possessing great wealth, falls in love with Lorenzo, a young Sicilian employee of her brothers. However, her brothers discover their love and become furious. They invite Lorenzo to their private garden under the pretenses of having lunch but then stab him in the back with a dagger in order to save their family's honour. They bury Lorenzo's body in the garden. He appears to the grieving Elizabeth in a vision and reveals his body's whereabouts. Elizabeth finds the body, removes the head, and hides it in a pot of basil that she tends to daily.
Gemmata:
In the seventh episode (based on Ninth day, tenth tale), the commoner Pietro and his wife Gemmata have a guest named Don Gianni who is staying with them. Their neighbor Zita is getting married, which means Gemmata can't stay with her, so all three must share the same house. Gemmata and Pietro sleep in the bedroom and Don Gianni is in the stable. Don Gianni, using his cunning, tells Pietro and Gemmata that Gemmata can be turned into horse and then back into a human, so she can be used to sow the fields of her husband's farm. Don Gianni can make this happen only with a special spell. The spell is a ruse: the doctor has imagined a ritual to enable him to have sex with the woman, in full view of her husband. Don Gianni strips Gemmata naked in front of Pietro and grabs her breasts, hair, back and bottom, and describes how each part will appear when she is a mare. At the last part he is about to stick his penis into her and calls it her "tail". Pietro screams that he doesn't want a tail. Don Gianni turns around and tells Pietro that his screaming ruined it so now she can't turn into a horse.
Heaven and Hell:
The eighth episode (based on Seventh day, tenth tale) involves two characters from Naples named Meuccio and Tingoccio who agree to tell each other about Heaven or Hell when they die. After a time, Tingoccio dies. Meuccio is afraid for his soul because he had sex out of wedlock with his girlfriend so many times. One night he has a dream in which his friend tells him that he is in Limbo, and though the angels knew of all his sins they do not consider sex a mortal sin as they had believed. Meuccio runs through the streets to his girlfriend and they have sex.
Epilogue:
Giotto admires his completed fresco, which illustrates episodes of the film, and muses "Why create a work of art when dreaming about it is so much sweeter?"
