The aim of the article is to analyze the missionary action of the Orthodox Church undertaken among Greek Catholics in the Recovered Territories of Poland following World War II. As a result of “Operation Vistula” the Orthodox and Greek Catholic population was settled in the Recovered Territories. As a result of the communist policy implemented by the communist authorities, the Orthodox Church took action to provide religious care to Greek Catholics. This policy was aimed at significantly weakening the Greek Catholic Church. It was also hoped that it would be liquidated. Despite the attempts made, the Greek Catholics preserved their identity, and after 1956 they began the process of building their own parish structure.
