The only traces which remain of Abū Sahl al-Qūhī's work on centers of gravity are the correspondence he maintained with Abū Is[hdotu]āq al-[Sdotu]ābi', and the first chapter of the Kitāb Mīzān al-[hdotu]ikma, which 'Abd al-Ra[hdotu]mān al-Khāzinī attributes to al-Qūhī and to Ibn al-Haytham, without distinguishing between their respective contributions. The author of the present article attempts to confront the texts and to analyse all the testimonies which have come down to us on this subject, which are susceptible of shedding light upon al-Qūhī's contribution and the importance of his work on centers of gravity.