Regarding al-Khwārizmī's religion, Toomer writes: Another epithet given to him by al-Ṭabarī, "al-Majūsī," would seem to indicate that he was an adherent of the old Zoroastrian religion.
Sobre a relixión de Al-Khwarizmi, escribe Toomer: Outro epíteto que lle deu Al-Ṭabari, "al-Majūsī," parecería indicar que foi un seguidor da vella doutrina do zoroastrismo.