Until the end of First World War, the territory of the present-day Diocese of Zrenjanin belonged to the Roman Catholic Diocese of Csanád. After the collapse of Austria-Hungary, region of Western Banat was incorporated into newly formed Kingdom of Serbs, Croats and Slovenes (later known as Yugoslavia). In 1923, the Apostolic Administration of Yugoslav Banat was created.
During World War I, the territory of present-day Diocese of Zrenjanin was under the jurisdiction of the Roman Catholic Diocese of Csanád. After the fall of Austria-Hungary, the region of Western Banat became part of the newly established Kingdom of Serbs, Croats and Slovenes (later Yugoslavia). In 1923, the Apostolic Administration of Yugoslav Banat was created.