In the Greek text of Mt. 16.18 Peter's name is Πέτρος, while the 'rock' is Πέτρα. Many have assumed an Aramaic substratum to the text whereby the same Aramaic term ﬤ'פּﬡ underlies both Greek words. An alternate view posits that while ﬤ'פּﬡ lies behind Πέτρα, a différent Aramaic term was most likely rendered by Πέτρα. This article examines the Aramaic and Syriac évidence afresh and at the same time proposes a methodology for studying such issues. It concludes that ﬤ'פּﬡ is a strong candidate for an original Aramaic background for Πέτρα.