Although the Decameron and the Canterbury Tales have often been linked, this is the first ever major study of the two most popular collections of medieval framed narratives to examine them both beyond shared general similarities and also to look at the search for individual analogue or sourcematerial, which has proved so inconclusive. Thus, the present study examines the texts and their internal dynamics primarily as a whole and reveals many surprising similarities which have not hitherto been seen.The two collections are examined in the light of their literary diversity, their shape as a form of quodlibet debate, their discussion of literature and its autonomy using the oppositions of utile-diletto and 'sentence'-'solaas', and the specific way that individual narratives are treated so as tocreate a labyrinthine web for the reader to both negotiate and enjoy.