It contains over 4,000 aḥādīth in 32 books (kutub) divided into 1,500 chapters (abwāb). About 20 of the traditions it contains were later declared to be forged; such as those dealing with the merits of individuals, tribes or towns, including Ibn Mājah's home town of Qazwin.
Sunni regard this collection as sixth in strength of their Six major Hadith collections. Nonetheless this position was not settled until the 14th century or later. Scholars such as al-Nawawi (d. 676/1277) and Ibn Khaldun (d. 808/1405) excluded the Sunan from the generally accepted books; others replaced it with either the Muwaṭṭaʾ of Imām Mālik or with the Sunan ad-Dārimī. It was not until Ibn al-Qaisarani's formal standardization of the Sunni cannon into six books that Ibn Majah's collection was regarded the esteem granted to the five other books.(source)