Ibn Ma`in has described him as a "Shi`a extremist," while Daraqutni calls him "Rafidi, extremist, but also reliable." Al-Jawzajani says that the man has "deviated." Al-Mas`udi says, "We have never seen anyone who is so outspoken in preaching his Shi`a views like `Adi ibn Thabit." In his Al-Mizan, al-Dhahabi describes him as "the learned scholar of Shi`as, the most truthful among them, the judge and Imam of their mosques. Had all the Shi`as been like him, their harm would have been minimized."

Then he goes on to document his biography and quote the views of the scholars cited above. He recounts the scholars who describe him as trustworthy such as Daraqutni, Ahmad ibn Hanbal, Ahmed al-`Ijli, Ahmed al-Nasa'i, placing on his name the initials of authors of all the six sahih books who quote him.

Refer to his hadith in both Bukhari's and Muslim's Sahih books as transmitted by al-Bara' ibn `Azib, `Abdullah ibn Yazid (his maternal grand-father), `Abdullah ibn Abu Awfah, Sulayman ibn Sard, and Sa`id ibn Jubayr. His hadith reported by Zarr ibn Habish and Abu Hazim al-Ashja`i is recorded in Muslim's Sahih. His hadith is quoted by al-A`mash, Mis'ar, Sa`id, Yahya ibn Sa`id al-Ansari, Zayd ibn Abu Anisa, and Fudayl ibn Ghazwan.