The adaptation covers eight of the 24 tales and contains abundant nudity, sex and slapstick humour. Many of these scenes are present or at least alluded to in the original as well, but some are Pasolini's own additions.
The film sometimes diverges from Chaucer. For example, "The Friar's Tale" is significantly expanded upon: where the Friar leads in with a general account of the archdeacon's severity and the summoner's corruption, Pasolini illustrates this with a specific incident which has no parallel in Chaucer. Two men are caught in an inn bedroom having sex. One is able to bribe his way out of trouble, but the other, poorer man is less fortunate: he is tried and convicted of sodomy—it does not occur to the judge that such an act cannot be committed by one person alone—and is sentenced to death. As a foretaste of Hell, he is burned alive inside an iron cage ("roasted on a griddle" in the words of one spectator) while vendors sell beer and various baked and roasted foods to the spectators.
Set in England in the Middle Ages, stories of peasants, noblemen, clergy and demons are interwoven with brief scenes from Chaucer's home life and experiences implied to be the basis for the Canterbury Tales. Each episode does not take the form of a story told by different pilgrim, as is the case in Chaucer's stories, but simply appear in sequence, seemingly without regard for the way that the tales relate to one another in the original text. All the stories are linked to the arrival of a group of pilgrims at Canterbury, among whom is the poet Geoffrey Chaucer, played by Pasolini himself.