Abstract: Andreas Osiander is considered by the historiography to be one of the few Reformers who were sympathetic to Jewish communities. Recent work by Anselm Schubert seems to qualify this. What is the real situation? An examination of Andreas Osiander’s writings on Judaism reveals his fascination with and expertise in Jewish culture, but also reveals the ambivalence of his relationship to Judaism when it came to taking action and promoting the Reformation in Nuremberg.