While Mutazilism had become marginalized in Sunni Islam by the VIth/XIIth century, the reception of Basran Mutazilī thought experienced a sudden rise among the Zaydīs of Yemen. Their Imams began officially supporting the transfer of Basran Mutazilī texts and doctrines to Yemen. As a result, an indigenous Basran Mutazilī school emerged and preserved numerous Mutazilī theological sources, which would otherwise have been lost. One of the most important representatives of this school was al-asan al-Raā (d. 584/1188). This article provides an outline of al-Raā’ biography and of his extensive body of works in order to show his importance for the spread of Basran Mutazilī thought among the Zaydī community.