Pulmonary rehabilitation in COVID-19 patients with pneumonia is associated with better treatment outcomes. However, existing protocols have never been evaluated in randomized control studies. The aim. To evaluate the effectiveness of newly-developed pulmonary rehabilitation protocol compared to basic Russian COVID-19 guidelines for patients with oxygenation index (OI) between 200 and 400 points without IMV. Methods. Based on literature reviews and own clinical experience, standard rehabilitation protocol was designed and tailored for specific needs of low-OI patients. Two clinical centers participated in the study and included total 73 patients in main group. Control group included 73 retrospective patients based in propensity score; this patients received standard protocol of early pneumonia activation from official COVID-19 guidelines. Ten-days clinical outcomes were assessed based on parameter distribution type. Results. Evidence show significant difference in required time of continuous oxygen support in (5.1 ± 3.3 vs 8.0 ± 4.6 days for main and control group respectively. Main group also had mildly better functional. We've observed less mortality in main group, but attribute it not to the program, but for growing experience of health professionals and decreased loads on health system. Malignancy as comorbidity was considered a significant cofactor also. Conclusion. New pulmonary rehabilitation protocol improves clinical outcomes in critical COVID-19 patients by decreasing the demand fox oxygen support.