The various contexts in which astrological knowledge found its way into Ashkenazi Jewish culture are identified, in an attempt to understand how these contexts influenced the study of astrology and shaped the associated modes of literary activity. A number of astrological doctrines gained a permanent place in the rabbinic batei midrash and yeshivot, where they played an important though ancillary function in the traditional curriculum. There were also tendencies to accord astrology a place as a socially approved practice, as documented in liturgical manuscripts and calendar texts. Finally, from the twelfth century on there was an increasing trend of separate literary works devoted to scientific and para-scientific issues. Although these works often appear in a mystical or esoteric guise, astrological concepts were among the most important issues discussed. It remains significant, however, that none of these historical phenomena in medieval Ashkenazi culture generated a systematic study of astrology or produced full expositions of astrology as an independent branch of human knowledge.