The article deals with the manuscript IOM, RAS Syr. 34, one leaf of parchment originating from the collection of Nikolai Likhachev. It contains a Syriac translation of selected documents of the First Ecumenical Council of Nicaea (AD 325): the introduction to the canons, a bilingual Greek-Syriac list of 42 bishops, and the first five canons of the council. Most of the texts are incomplete and damaged. The present article focuses mainly on the study and commented publication of the five Nicaean canons from IOM, RAS Syr. 34. On the basis of comparative textual research the author aims to show the place of the St. Petersburg manuscript in the history of Syriac translations of the canons.