Aim. To establish biomarkers for clinical, radiological, and laboratory severity of COVID-19 infection and to identify their relationships. Materials and methods. A retrospective study was carried out which included 155 patients undergoing treatment at the Hospital for War Veterans No. 3 with a confirmed diagnosis of novel coronavirus infection caused by nCoV from April 6 to June 10, 2020. All patients underwent clinical and laboratory examination. An intergroup statistical analysis of clinical and laboratory parameters was carried out depending on the criteria of clinical severity and severity of radiological signs of chest organ pathology according to computed tomography (CT). Results. Patients with mild COVID-19 showed a lower level of leukocytes, urea, creatinine, bilirubin, and aspartate dehydrogenase (AsAT), as opposed to the corresponding levels in patients with extremely severe course of the disease. A lower level of calcium in the peripheral blood was found in patients with severe COVID-19, along with an increase in blood glucose. Patients from the CT1 group as well as patients with a clinically mild course of the novel coronavirus infection had significantly lower levels of neutrophils, urea, creatinine, AsAT, and blood glucose and a higher level of blood calcium in comparison with patients with various CT patterns. In the group of patients with a fatal outcome, cardiovascular diseases were significantly more often detected, as opposed to the discharged patients. Conclusion. A number of biomarkers characterizing the severity of the novel coronavirus infection caused by the SARS-CoV-2 virus have been identified. However, the revealed differences in the laboratory markers of the clinical and radiological severity of the disease do not currently allow to give a clear answer about the nature of the relationship between the clinical severity of the disease, CT findings, and laboratory indicators of COVID-19 severity.