The Πόνημα ἰατρικόν by Michael Psellos is a didactic poem on medicine. The work, as it has been preserved until today, lacks a programmatic prologue, nevertheless, in a brief passage, introduced between verses 531-537, the author states that his intention is not to gather everything about this discipline, but to stir up the appetite for it in his learned friends using the charm of the verses. Taking into account the intentions expressed by the author himself, our aim is to analyze, by comparing and contrasting the poem with its sources (Paul of Aegina, Theophilus Protospatharius and Palladius of Alexandria), what kind of medical contents he selects from these sources and how he adapts and uses them, in order to verify how Psellos' purpose is fulfilled. [ABSTRACT FROM AUTHOR]