Abstract: This essay aims at investigating the concept of doulopolis, since it seems to be contradictory: ancient attestations (mainly proverbs) declare it is not possible that a city of slaves really exists but, along with this, they also attest some occurrences of cities inhabited only by slaves. Importance will be paid to Aristotle’s thought (often neglected on doulopolis by scientific literature), since a polis is not only a settlement of people but a community that aspires to be happy (eudaimon). As a result, in this axiological view of what a polis is, a city of slaves would not be a real city and a real doulopolis does not exist as polis but only as an agglomerate.