Introduction: The assessment of the level of consciousness in patients with acute brain injury is a mandatory first step of neurological examination. There is a need for clinical scales which allow to assess the level of wakefulness and degree of patient non-responsiveness in 2-3 minutes. The Full Outline of UnResponsiveness (FOUR) scale is an optimal tool for such clinical assessment, which focuses on eye response, motor response, brainstem reflexes, and respiratory pattern. The absence of an officially translated and validated version impedes the use of FOUR scale in Russia, while the use of non-validated clinical scales carries a risk of erroneous diagnosis and reduces the quality and information value of research studies. Study aim: to develop an official Russian language version of the FOUR scale, taking into account its linguistic and cultural characteristics as part of the validation st udy. Materials and methods: The first stage of the validation process was completed, consisting of the linguistic and cultural adaptation of the FOUR scale. Medical professionals (Russian and English native speakers) performed forward and back translations of the original scale. The developed version then underwent review by the Expert Commission, which included a linguist, neurologists, anaesthesiologists and intensive care specialists. The next step was a pilot test of the scale. Results: The main difficulties in the translated text of the scale were solved during the first meeting of the Expert Commission. Then, taking into account the inclusion and exclusion criteria, a pilot test was performed by assessing 15 patients with the developed version of the FOUR scale. The statistics of this cohort are presented. Investigators had no difficulties in understanding and interpreting the scale instructions during the pilot test. Based on the results, the final version of the scale was adopted. The Russian version of the scale text with instructions and illustrations is presented in this paper. Conclusion: Translation, linguistic and cultural adaptation of the FOUR scale was conducted at the Research Centre of Neurology (Moscow, Russia). For the first time, the Russian version of the scale is officially presented and recommended for widespread use in clinical and research practice in Russia and other Russian-speaking countries based on the results of pilot testing. The next publication will present the results of the evaluation of psychometric properties (reliability, sensitivity, etc.) of this version of the scale. © 2019 Sovero Press Publishing House. All rights reserved.