This essay explores the phenomenon of the translation of scientific works from European languages into Yiddish from the early sixteenth century through the late eighteenth century. By following the trajectory of texts and ideas from the non-Jewish realm to the Ashkenazi Jewish vernacular, it draws attention to the ways in which cultural and scientific innovations reached Jewish readers of various classes, spaces, and genders well beyond the narrow elite of rabbinically or university-trained Jews. The essay challenges the notion that there existed in early modern Europe a neat division of labor between Hebrew, the language of the learned elite, and Yiddish, the language of the Jewish masses. It also contributes to recent scholarship calling into question the prominence of the Jewish Enlightenment (the Haskalah) as a harbinger of Ashkenazi interest in non-Jewish knowledge in general, and science in particular. Mapping the hitherto overlooked interactions between Yiddish readers and writers and early modern scientific thought, this essay opens avenues into new research on the complex relationships between the interrelated corpora of early modern Jews and Christians, physicians and rabbis, scholars and laypeople.