Introduction. Even now - a year after the pandemic announcement by WHO, there is lack of clinical evidence to confirm the efficacy of the majority of anti-COVID drugs, evenly for general and critically ill patients. Objective. To estimate the efficacy and safety of some anti-COVID-19 drugs as well as the impact of the demographic data and comorbidity on clinical outcomes of critically ill patients. Materials and methods. The single-center retrospective cohort study was performed on critically ill patients admitted to the ICU of Moscow Municipal Hospital No. 68 from March 6 to June 3, 2020. Anthropometric parameters, severity of the condition and comorbidities, as well as CT data, treatment in the ICU, duration of mechanical ventilation and the patients’ length of staying the ICU were taken into account and analyzed. Results. Overall, 403 patients (231 male, average age: 62.4 ± 15.3 years, range from 21 to 97 years) were enrolled into the study. In hospital mortality rate appeared to be 44.9 % (181/403) and was equal for men and for women (p = 1,000). The application of low molecular weight heparin was the single one significant predictor of mortality reduction according to the results of multivariate analysis - HR = 0.742 (0.545-0.991), p = 0.045. The main unmodifiable predictors for mortality elevation in the ICU were: age 65+ (RR 2.116 [1.680-2.664], p < 0.001) and Charlson’s comorbidity index (HR 1.136 [1.087-1.188], p < 0.001). The group of patients with a fatal outcome had a higher comorbidity index, the number of points on the SOFA scale (p < 0.001), as well as a larger median number of days in the ICU (p = 0.012).