This paper explores the presence of phraseological expressions in Alfredo Panzini’s Dizionario Moderno, considering the first edition (1905) and the last edition edited by the author (1935). The rich phraseological variety of the dictionary reveals itself in various aspects: spoken and dialectal language, literary quotations, co-presence of various modern and ancient languages, specialist languages in their relationship with the common language. In the last paragraph, the essay analyses the role of phraseology in the light of Panzini’s linguistic ideas: according to the author, phraseological expressions are a vital and fundamental element of every language. Their presence in the Dizionario Moderno thus shows Panzini’s attention to the evolution of the Italian language in the first decades of the 20th century.