This article examines the functions and aesthetic evaluation of prologues in ancient Greek drama based on classical sources. Through a comprehensive analysis of Aristotle’s Poetics and Rhetoric, Aristophanes’ comedies, and fragments of other comic poets (such as Machon and Antiphanes), the study explores how prologues were perceived in antiquity — both in terms of their structural purpose and their qualitative assessment. A key distinction is made between tragic and comic prologues: while clarity was prioritized in tragedy, comedy demanded additional elements of entertainment and humor in order to engage audiences. The central focus of the article is the concept of the “cold” (ψυχρός) prologue, particularly in reference to critiques of Diphilus’ comedies. The term is analyzed in its various possible meanings — ranging from “unclear” and “tedious” to “unfunny” — and contextualized within the framework of ancient literary criticism. The discussion incorporates passages from Xenophon, Theophrastus, and comic fragments to demonstrate how ψυχρός functioned as a pejorative label, often associated with failed attempts at humor, excessive complexity, or dull exposition. Additionally, the article examines an anonymous comic prologue (Com. Adesp. fr. 1008 K–A) to illustrate how excessive detail or length could undermine a prologue’s effectiveness. The study concludes that an ideal prologue in ancient drama balanced exposition, clarity, and entertainment, with “coldness” arising from a disruption of this equilibrium. By reconstructing ancient evaluative criteria, the article sheds light on the performative and rhetorical expectations of prologues, contributing to broader discussions about genre-specific aesthetics in Greek theater.