Although numerous studies have dealt with expressions of emotions in Greco-Roman antiquity, less attention has been given to poetry as an artistic form deliberately meant to shape and transform human affectivity. This essay examines how ancient authors characterize lyric, dramatic, and didactic poetry as a means to influence affects, exemplifying with varieties of fear. The emphasis is on how poetic works can decrease or increase fear-related affects, such as panic on the battlefield, fear of death, horror, and existential anxiety. The examples range from archaic Greek lyric poetry (Tyrtaeus), to views about tragedy in classical Greek philosophy (Plato and Aristotle) and, finally, to didactic poetry in Rome (Lucretius).