Aristotle divided poetry into three main categories: epic, tragic, and comedic. These three genres can then be further separated into several sub-genres.

In Poetics, Aristotle describes epic poetry as being a narrative form of poetry that contains a central plot. It consists of multiple characters whose voices the poet can take on to further the narrative. Epic poetry also uses a one-verse form.

Tragic poetry is defined in Book VI as "an imitation of an action that is serious, complete, and of a significant importance." It uses poetic embellishments and, unlike epic poetry, is not narrative. Tragic poetry tells of human actions and their often serious and dire consequences. It is meant to evoke pathos in its audience.

Comedic poetry is meant to show the ridiculousness and the absurdity that is part of human nature. People are meant to be shown as worse than they really are. However, Aristotle notes in several works, these flawed humans are not meant to be malevolent, just laughable and deserving of mockery. The surviving text of Poetics does not actually address comedy. However, scholars believe that it was treated in a now lost part of the work.

In his Poetics, Aristotle distinguishes two main genres of poetry and several sub-genres. the two main genres are epic and dramatic poetry. They are distinguished by drama being a type of poetry the imitates by means of mimesis exclusively and epic one that imitates by a combination of mimesis and diegesis. Dramatic poetry is sub-divided into comic and tragic by both subject matter (people worse or better than average) and treatment (serious vs. humorous). Aristotle's treatment of comedy originally followed his discussion of tragedy in teh Poetics but is no longer extant. Aristotle also discusses choric poetry, and especially the origin of tragedy in the dithyramb.