Direct critical attack of the coronavirus on the alveoli and the excessive release of a large number of cytokines (IL-6, IL-1, TNF-α, etc.) provides suitable conditions for the further development of acute respiratory distress syndrome (ARDS) and severe acute respiratory failure. Serious decrease in blood oxygenation often lead to the deterioration of macro- and microcirculation, irreversible brain damage and hence, persistent neurological and mental disorders despite background intensive therapy and adequate respiratory support. Therefore, the aim of our open prospective observational study was to investigate the neuroprotective and antioxidant effectiveness of montelukast-acetylcysteine combination therapy for brain protection in patients with COVID-19 viral pneumonia. A study was performed for five hundred seventy-eight (n=578) outpatients who were tested positive for novel coronavirus (SARS-CoV-2) by nasopharyngeal swap. The median age of patients was 62±17.45 years. In addition to clinical features and RT-PCR results, chest CT and chest X-ray (CXR) with high sensitivity were also very helpful for the early identification of viral pneumonia and COVID-19 disease assessment. Considering the severity of Covid-19 pneumonia and the level of arterial oxygen saturation (transcutaneous hemoglobin oxygen saturation) on room air, all patients were divided into three major groups. Group 1 (n=288) consisted of patients with a mild shift in oxygen saturation (SpO2 ≥ 95%) and well-defined pulmonary lesions (within 1-2 segments) without concomitant diseases; the second group (Group 2, n=250) included patients with clinical manifestations of moderate severity associated with a current saturation of 90-95% (SpO2) and small pulmonary lesions on chest X-ray in the presence of concomitant diseases: arterial hypertension (stage III) or CHF (FC/NYHA-2), coronary heart disease or type 2 diabetes, cancer, tuberculosis, etc. Most of the patients in third group (Group 3, n=48), during imaging studies, showed bilateral lung affection with low and peripheral distribution (with both - either ground glass opacities or multiple pulmonary nodules) and cardiomegaly. The respiratory failure of stage II-III (current oxygen saturation SpO2 75-90%), high respiratory rate (≥25 per minute), hemodynamic impairment (BP≤100/60 mm Hg. Art., heart rate ≥125/min) were the most common objective clinical findings seen in this subset of patients. Laboratory changes included leukopenia less than 4.0x109/L or leukocytosis (≥10.0X109/L). Background respiratory support with low-flow oxygen therapy and combined pharmacotherapy, where, along with montelukast and acetylcysteine, patients were prescribed a cephalosporin, a fluoroquinolone, an antifungal drug, a histamine blocker, an antiplatelet agent, a complex of B vitamins, led to a significant improvement in symptoms and laboratory parameters during the course of the disease. The mean values of the blood biomarkers (CRP - 21.46±4.43 mg/l, LDH - 410.71±40.63 U/l, procalcitonin - 1.08±0.31 ng/ml, and ferritin - 270.43±27.23 ng/ml) return to normal by the 20th day after the fever subsides. Laboratory parameters before and after treatment course showed statistically significant differences between variables (p<0.05). No patient in Group 3 received JAK inhibitors (tofacitinib and baricitinib), IL-6 (olokizumab), IL-17A (netakimab) and glucocorticosteroids, however, recovery rates were completely good. Assessment of the patient's neurological status (based on the NIHSS scores) revealed no signs of neurological changes. Thus, based on the data given, it can be concluded that the high efficacy of the acetylcysteine/montelukast combination (as neuroprotectors) in pneumonia caused by COVID-19 is due to the effect of drugs on key mechanisms of pathogenesis: reduction of oxidative stress as drugs (combination) ensuring the free radical scavenging; stimulation of glutathione synthesis; suppression of cytokine storm; reduction of bronchospasm, mucus secretion and airway edema; lowering of BBB permeability and the ability to improve cerebral microcirculatory perfusion in the presence of antiplatelet agents. In conclusion, the combination of montelukast and acetylcysteine may provide an effective, safe, multicomponent approach to the prevention of hypoxic brain injury in patients with COVID-19 pneumonia.