Ibn Abi Sadiq al-Naishaburi, Abu al-Qasim ‘Abd al-Rahman ibn ‘Ali was an 11th century Persian physician from Nishapur in Khorasan.
He was a pupil of Avicenna. As he composed a popular commentary on the Aphorisms of Hippocrates, he was known in some circles as "the second Hippocrates" (Buqrat al-thani). Ismail Gorgani, the author of Zakhireye Khwarazmshahi, completed his studies under his guidance.
His commentary on the Hunayn ibn Ishaq's Questions on Medicine, however, may have been even more popular, judging from the large number of copies preserved today. Ibn Abi Sadiq also wrote a commentary on the Prognostics of Hippocrates, on Galen's treatise On the Usefulness of the Parts, and on Razi's treatise Doubts about Galen (Shukuk ‘alá Jalinus). According to the medieval biographical sources, he completed the commentary on Galen's On the Usefulness of the Parts in the year 1068 AD, which provides us with the one firm date in his biography.