This study aims to analyze the mechanisms of canonization, based upon Finnish and Estonian short stories. The author first presents the theoretical works about literary canons and the frequent debates that surround that notion. He then studies the respective roles of the most important canonizing instances (critical articles, critical works, literary prizes, anthologies, translations, educational system) in Finland and Estonia. Attention is particularly drawn toward critical reception in literary journals, and the way classical short stories are evocated in literary handbooks. Case studies dealing with precise authors and themes lead to several proposals of new theoretical tools for the diachronic study of canons and the description of canonization-related phenomena and the different circumstances which can help or hinder the canonization of short stories.