Rad se bavi institutom ostracizma istražujući razloge njegova nastanka, svrhu koja se njime željela postići te značaj koji je imao za razvoj atenskog polisa i njegovu veličinu. Pri tome polazi od pitanja je li ostracizam bio moćno sredstvo zaštite atenskog ustava, jedna od uspješnijih reformskih mjera, oruđe jačanja osobnih moći trenutnih vođa ili tek sredstvo rješavanja nekih kriznih situacija u društvu. Prikaz okolnosti njegova donošenja, načina funkcioniranja te posljedica koje je imao za pojedine atenske građane i polis u cjelini potvrđuje da se radi o dobro osmišljenom institutu koji se kretao u granicama dovoljno širokim da se može lako primijeniti u slučaju potrebe, a istovremeno dovoljno određenim da se ne može zloupotrebljavati. Činjenica da je za ostraciranje pojedinca volja demosa bila nezaobilazna i da se ne može govoriti o velikom broju ostraciranih potvrđuje pak da je demosu bilo stalo do njegovih istaknutih i časnih građana te da je do odluke o tome treba li netko napustiti Atenu dolazilo iznimno, sa spoznajom o tome što polis dobiva, a što gubi. Iz toga treba zaključiti da su Atenjani bili svjesni opasnosti koju je ovaj institut u sebi nosio, ali i njegovih dobrih strana koje su štitile atenski predak. Nije slučajno što se kraj primjene ovog instituta poklapa s vremenom kada je atenska demokracija počela gubiti zanos. On je imao svoj smisao dok je demosu bilo stalo.This paper deals with the institute of ostracism by exploring the reasons for its occurrence, the purpose that it was supposed to attain and the significance it had to the development of the Athenian polis and its size. The starting question is whether ostracism was a powerful tool for the protection of the Athenian constitution, one of the more successful reformative measures, a tool for strengthening personal powers of the current leaders, or merely a means of solving crisis situations in the society. The account of the circumstances of its passing, the way it functioned and the consequences it had for certain citizens of Athens and the polis as a whole confirm that this is a very well-designed institute that operated within wide enough limits that made it easy to apply if the need arose, while remaining specific enough so that it could not be abused. The fact that the will of the demos was a prerequisite for ostracizing an individual and that the number of ostracized people is not large, proves that the demos cared for its distinguished and honourable citizens and that the decision on whether one of them should leave Athens was reached very rarely, with awareness of what was gained and what was lost by the polis. What can be deduced from this is that the citizens of Athens were aware of the dangers inherent to this system, but also of all of its positive sides that protected the social order in Athens. It is not a coincidence that the end of the application of this system coincides with the time when democracy in Athens started to lose its momentum. Ostracism made sense while the demos cared