A 4th century collection, in 8 books, of independent, though closely related, treatises on Christian discipline, worship, and doctrine, intended to serve as a manual of guidance for the clergy, and to some extent for the laity. It purports to be the work of the Twelve Apostles, whose instructions, whether given by them as individuals or as a body, are supposed to be gathered and handed down by the compiler, Clement of Rome, the authority of whose name gave weight to more than one such piece of early Christian literature (see also Clementine literature). Where known they were

The first 6 books are based on the Didascalia Apostolorum, a lost treatise of the third century, of Greek origin, which is known through Syriac versions. The 7th book is based on the Didache. The 8th book is a mixed compilation. The introductory chapters (i-ii) have for their foundation a treatise entitled "Teaching of the Holy Apostles concerning Gifts", possibly a lost work of Hippolytus. The 3rd chapter appears to be a work of the compiler. Chapters (iv-xlvi) present difficulties the varied solution of which divides scholars as to

The Apostolic Constitutions were rejected as canonical by the Decretum Gelasianum and the Sixty Books canon and the Quinisext Council in 692 because they were said to contain heretical interpolations. They were accepted as canonical by John of Damascus and the Ethiopian Orthodox 81 book canon.

From John William Donaldson's introduction: "There has always existed a great diversity of opinion as to the author and date of the Apostolical Constitutions. Earlier writers were inclined to assign them to the apostolic age, and to Clement; but much discussion ensued, and the questions to which they give rise are still unsettled. The most peculiar opinion in regard to them is that of Whiston, who devoted a volume (vol. iii.) of his Primitive Christianity Revived to prove that "they are the most sacred of the canonical books of the New Testament; "for "these sacred Christian laws or constitutions were delivered at Jerusalem, and in Mount Sion, by our Saviour to the eleven apostles there assembled after His resurrection.""