This codex, dated to the fourth century C.E., originally contained the entire Bible in Greek. The pages of this manuscript are made out of fine vellum, and the text is written in uncial script. (See MANUSCRIPTS; UNCIAL.) The poetic books are presented in two columns of text per page, while the rest of the Bible is laid out in three columns per page.

Because it has suffered a number of losses, the codex is not complete. It contains 759 leaves out of an original total of about 820. So the text now begins with Genesis 46:28 and lacks a part of Psalms, Hebrews 9:14 to 13:25, and all of 1 and 2 Timothy, Titus, Philemon, and Revelation. It is believed that the codex was produced in Egypt, but no definite information on its origin has survived. It is known to have been in the Vatican Library from as early as the 15th century. However, it was not made available to scholars until the 19th century.

Because of its antiquity and excellent quality, this codex is considered to be one of the most valuable manuscripts of both the Greek Septuagint text and the text of the Christian Greek Scriptures. As such, it is one of the key sources used by modern Bible translators. Scholars have used this authoritative manuscript, along with Codex Sinaiticus and Codex Alexandrinus, to identify and correct additions and scribal errors that were introduced into later Bible manuscripts.​—See Media Gallery, “Codex Vaticanus​—End of Mark’s Gospel” and study note on Joh 7:53.