The Old Turkic runiform inscription Kuttu I was found by B. M. Kindikov and A. G. Chekurashev in 2016 (Kindikov and Kindikov 2018: 35) at the footstep of the mountain Kuttu near the village Bichiktuu-Boom, known for its numerous Old Turkic inscriptions. The authors of this article documented it using the methods of digital photogrammetry in 2017. The article presents the first description of the inscription’s physical properties, as well as its transliteration, transcription and interpretation.