Aim. To investigate the methods of early diagnosis of oxaliplatin-induced peripheral neuropathy (PN). Materials and methods . The study included 52 patients with diagnosis of metastatic colorectal cancer receiving 1st line polychemotherapy per the mFOLFOX6 scheme ± targeted therapy who prior to each cycle filled out the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy (EORTC QLQ CIPN 20) and were subject to neurological examination using the Neuropathy Disability Scale (NDS). Results . The analysis included 28 patients who completed polychemotherapy: 16 (57,2 %) men and 12 (42,8 %) women, mean age 60.0 ± 10.0 years. Fridman’s two-way analysis of variance by ranks showed significant changes in the scores (sensory, motor, autonomic) of the EORTC QLQ CIPN 20 questionnaire with the increase in the number of chemotherapy cycles (р = 0.001). Significant increase in the sensory and motor scores was observed after the 3rd cycle, in the autonomic – after the 6th cycle. Significant increase in NDS score was observed starting at the 3rd cycle, and vibration sensitivity on the medial ankle or at the base of the 1st toe significantly decreased after the 1stcycle. Median number of cycles at which oxaliplatin dose was reduced or the drug was discontinued due to clinically significant symptoms of PN irrespective of questionnaire results and neurological examination was 6. Conclusion. According to the results of the study, the following conclusions were made: 1) sensory scale of the 3-part EORTC QLQ CIPN 20 questionnaire (9 questions of 20) or motor scale (7 questions of 20), vibration sensitivity can be considered as stand-alone informative tests; 2) in a large patient cohort, NDS score increase to 5, EORTC QLQ CIPN 20 sensory scale score increase to 12 and higher or decreased vibration sensitivity on the medial ankle or at the base of the 1st toe to 4.5 arbitrary units should be considered early manifestations of PN; 3) for a routine algorithm, it is acceptable to consider a combination of 9 questions of the sensory or 7 questions of the motor scales of the EORTC QLQ CIPN 20 questionnaire and evaluation of vibration sensitivity on the medial ankle or at the base of the 1st toe to decide on oxaliplatin dose reduction or measures for prevention of peripheral neuropathy symptom worsening.