Mar Pethion (d. 449) was a famous martyr under Yazdegerd II. In this study originally printed in Analecta Bollandiana, Corluy, after some brief prolegomena, presents the Syriac text of Mar Pethion's martyrdom on the basis of British Library Add. ms. 12174, together with a Latin translation. The text is printed with the Syriac on top, the Latin translation below, and a running outline of the narrative is given in the margins to the translation, which is also annotated with observations on Persian terms and names, and biblical citations are also noted.