The present volume offers the first critical edition, accompanied by an English translation, a commentary, and an introductory study, of Liber nativitatum (Book of Nativities) and Liber Abraham Iudei de nativitatibus (Book on Nativities by Abraham the Jew), two astrological treatises in Latin that were written by Abraham Ibn Ezra or attributed to him, and whose Hebrew source-text or archetype has not survived.