For a long time historians have neglected the comparison between the Holy Roman Empire and the Kingdom of Poland (or Poland-Lithuania), while recent studies have begun to highlight certain structural similarities of both early modern realms. Developments in the first half of the sixteenth century allow us to observe parallel developments in both political and religious reform movements and in attempts to develop the Reichstag and the Sejm. In this context, this article aims to compare the role of oratory in both assemblies in order to outline similarities and differences in the institutional functioning and political culture in the Holy Roman Empire and Poland. Recent research has emphasized that the representative function of early modern diets should not be reduced to a mere negotiation of political or religious matters between representatives of several estates, regions or personal jurisdictions. This remains one aspect of representation among others like the embodiment of the realm and the role of the diet as a social and political model and mirror of society as a whole. In this regard, oratory played a crucial role not only by organizing the technical procedures of the negotiations, but also as ceremonial acting which created hierarchies. Therefore, if political speech is understood to be acting and simultaneously a part of ceremonial and procedure, this allows us to point out the dynamic aspect of the recurrent attempts to renegotiate the existing hierarchies within the diets. Furthermore, even though the role and importance of parliamentary oratory in the Holy Roman Empire and Poland was significantly different, in both cases there are issues of textualization in the course of bureaucratization and its impact on the parliamentary speech.