The Gospel of Mary is found in the Berlin Gnostic Codex (or Papyrus Berolinensis 8502, as this ancient collection of Gnostic texts is labeled for archival reasons). This very important and well-preserved codex was apparently discovered in the late-nineteenth century somewhere near Akhmim in upper Egypt. It was purchased in 1896 by a German scholar, Dr. Carl Reinhardt, in Cairo and then taken to Berlin.

The book (or "codex", as these ancient books are called) was probably copied and bound in the late fourth or early fifth century. It contains Coptic translations of three very important early Christian Gnostic texts: the Gospel of Mary, the Apocryphon of John, and the Sophia of Jesus Christ. The texts themselves date to the second century and were originally authored in Greek. (In academic writing over the last century, this codex is variably and confusingly referenced by scholars as the "Berlin Gnostic Codex", the "Akhmim Codex", PB 8502, and BG 8502).