He was a Sunni Shafi muhaddith. He followed the Ash'ari creed in Islamic theology. He was the author of Sahih al-Bayhaqi, also known as Sunan al-Kubra, and Shu'ab al-Iman.

Belonging from Sabzevar, Al-Bayhaqi was a prominent senior pupil of the scholar Al-Hakim. He lived in Nishapur and became a scholar of the Shafi'i school. He collected, organized and analyzed Shafi'i statements and beliefs, and later on, compiled his massive hadith collection, the Sahih al-Bayhaqi, which is among the largest Sunni hadith collections, and possibly, the largest ever.