The Abhidhamma Piñaka is the third division of the Tipiñaka, the sacred scriptures of Buddhism, the other parts being the Sutta Piñaka and the Vinaya Piñaka. It is made up of seven books Ý the Dhammasaïgani, the Vibhaïga, the Dhàtukathà, the Puggalapa¤¤atti, the Kathàvatthu, the Yamaka and the Paññhàna. The books of the Abhidhamma Piñaka are generally later than both the Sutta and the Vinaya Piñakas and may have reached their present form several hundred years after the Buddha's passing. Tradition attributes them all to the Buddha, but there is no mention of this in the Abhidhamma Piñaka itself, nor is there any mention of the Abhidhamma Piñaka in either the Sutta or the Vinaya Piñakas. However, there is nothing in the Abhidhamma Piñaka that contradicts the Buddha's teachings; the difference is of approach, not content. See Abhidhamma and Saïkassa.
Guide to the Abhidhamma Piñaka, Nyanatiloka, 1950.