The study examines how the intensification of anti-Semitism, the growing militant public mood after World War I and especially its loss, and the introduction of numerus clausus in 1920 triggered dissimilationist efforts in the policy of the Pest Israelite Congregation, which had previously been promoting assimilation in the 19th century. Using various types of sources, the elements of the new congregational policy reform are interpreted, focusing on the life of a specific synagogue community (Páva Street Synagogue, Budapest).