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.
Prior to World War I, the territory now encompassed by the Diocese of Zrenjanin belonged to the Roman Catholic Diocese of Csanád. Following the disintegration of Austria-Hungary, Western Banat became part of the Kingdom of Serbs, Croats and Slovenes (later Yugoslavia). In 1923, the Apostolic Administration of Yugoslav Banat was established.