In Italy, anti-Protestantism became a significant theme in reactionary polemics during the Risorgimento and the post-unification period of the 19th century. Although it waned around 1900, the anti-Protestant offensive resumed after the First World War. Between the early 1920s and the mid-1950s, the Catholic Church’s hostility toward the Protestant presence and mission in Italy developed into a significant social and political phenomenon. It succeeded in influencing both the attitude of the Italian state and the legislation on religious freedom. Reconstructing Catholic anti-Protestantism, Paolo Zanini shows that attitudes toward Protestant denominations were among the elements of continuity between Fascism and the first decade of the post-war Republic.