The new coronavirus infection COVID-19 is often accompanied by the development of a cytokine storm in patients. Сytokine hemoadsorption is used to reduce cytokine levels along with anti-cytokine therapy. Criteria for the effectiveness of the cytokine hemoadsorption in patients with severe COVID-19 remain undeveloped. Purpose of the study: based on clinical and laboratory indicators, to develop a model and criteria for assessing the effectiveness of the cytokine hemoadsorption for the treatment of the cytokine storm in patients with severe COVID-19. The non-interventional observational clinical study included 171 patients (119 men, 52 women) aged 54± 12 years diagnosed with COVID-19 who were treated at City Hospital no. 40 of St. Petersburg during 2020–2021. The patients were assessed for clinical and biochemical blood parameters, the clinical state according to the NEWS, SOFA, PSI, and the cytokine hemoadsorption to reduce cytokine levels. Endpoints were biological death or discharge. The prognostic significance and threshold criteria for assessing the effectiveness of the cytokine hemoadsorptio were determined by constructing a “tree classification”. In 171 patients with severe COVID-19 infection, the most significant indicators of survival during the cytokine hemoadsorption were determined: age, time of onset of the cytokine hemoadsorption, Charlson index, NEWS, PSI, SOFA scale values, volume of lung damage on CT, D-dimer levels, LDH and CRB. For these indicators, odds ratios were determined and threshold values were obtained that affect the effectiveness of the cytokine hemoadsorption. Using the logistic regression method, a comprehensive prognostic model was built to assess the effectiveness of cytokine hemoadsorption in patients with severe COVID-19 with a sensitivity of 89 %, specificity of 70 %, and diagnostic accuracy of 80 %. The most significant indicators of patient survival during the cytokine hemoadsorption were determined and, on its basis, the prognostic model to assess the effectiveness of the cytokine hemoadsorption procedures in patients with severe COVID-19 was developed.The new coronavirus infection COVID-19 is often accompanied by the development of a cytokine storm in patients. Сytokine hemoadsorption is used to reduce cytokine levels along with anti-cytokine therapy. Criteria for the effectiveness of the cytokine hemoadsorption in patients with severe COVID-19 remain undeveloped. Purpose of the study: based on clinical and laboratory indicators, to develop a model and criteria for assessing the effectiveness of the cytokine hemoadsorption for the treatment of the cytokine storm in patients with severe COVID-19. The non-interventional observational clinical study included 171 patients (119 men, 52 women) aged 54± 12 years diagnosed with COVID-19 who were treated at City Hospital no. 40 of St. Petersburg during 2020–2021. The patients were assessed for clinical and biochemical blood parameters, the clinical state according to the NEWS, SOFA, PSI, and the cytokine hemoadsorption to reduce cytokine levels. Endpoints were biological death or discharge. The prognostic significance and threshold criteria for assessing the effectiveness of the cytokine hemoadsorptio were determined by constructing a “tree classification”. In 171 patients with severe COVID-19 infection, the most significant indicators of survival during the cytokine hemoadsorption were determined: age, time of onset of the cytokine hemoadsorption, Charlson index, NEWS, PSI, SOFA scale values, volume of lung damage on CT, D-dimer levels, LDH and CRB. For these indicators, odds ratios were determined and threshold values were obtained that affect the effectiveness of the cytokine hemoadsorption. Using the logistic regression method, a comprehensive prognostic model was built to assess the effectiveness of cytokine hemoadsorption in patients with severe COVID-19 with a sensitivity of 89 %, specificity of 70 %, and diagnostic accuracy of 80 %. The most significant indicators of patient survival during the cytokine hemoadsorption were determined and, on its basis, the prognostic model to assess the effectiveness of the cytokine hemoadsorption procedures in patients with severe COVID-19 was developed.