During World War II conversion came to mean something completely different than during the pre-war period: it became one of the survival strategies used by Jews on the territories under German occupation. Some Jews changed their religion because they married a Catholic. For others it was an escape from the categorization under German law and inclusion into the group with which, as they declared, they had had little in common. Others still saw baptism as a real chance of surviving the occupation. Conversion was a path to obtaining ‘Aryan’ papers, and thus acquiring a new identity necessary to survive beyond the walls of the Cracow ghetto and Płaszów camp. The objective of this article is to focus on the history and declared motivations of those who decided to apply for conversion after the outbreak of World War II. The archive of the Metropolitan Curia in Cracow includes documents and applications submitted by people intending to convert. That process began with the occupation and was officially and successfully continued almost until the end of 1942. This date is connected with the German ban on baptizing Jews under threat of severe punishment introduced on 10 October 1942. However, Jews continued to be baptized, though in secret, without applications to the Metropolitan Curia or public statistics.