Aim: to analyze the clinical efficacy and safety of oxyethyl ammonium methyl phenoxy acetate for the outpatient treatment of acute respiratory viral infections (ARVI) in adults and adolescents. Patients and Methods: An observational, open-label, postregistration study was conducted. The study group included 122 patients (75 adults and 47 adolescents). All study group patients were prescribed with oxyethyl ammonium methyl phenoxy acetate (tablets) in addition to symptomatic therapy. Treatment course duration was 8 days. The comparison group included 50 patients (30 adults, historical control, and 20 adolescents) who received symptomatic therapy for ARVI only. A prospective-retrospective analysis of disease clinical course by studying medical records was performed. Results: on days 3–5 after starting therapy, the proportion of patients with severe ARVI symptoms and fever reduced by 42.0% in the study group adults and only by 10.0% in the comparison group adults (p=0.001). In the study group adults, fever reduced significantly faster (p≤0.05) than in the comparison group adults. On days 3–5 after starting therapy, asthenia persisted in 47.3% of study group adults and 70% of comparison group adults (p=0.002). In the study group adolescents, fever duration was 2.5 days less than in the comparison group adolescents (p ≤0.05). Only 10 study group adolescents (21.2%) still had asthenia on days 3–5 after starting therapy, which is 2.4 times less common than at baseline and 1.9 times less common than in comparison group adolescents. No ARVI complications that required continuation of treatment, involve other specialists, or the use of additional examinations and treatments were reported in both groups. Conclusion: in an outpatient setting, when a doctor needs to make a decision on complex therapy based only on clinical manifestations, the use of ethyl ammonium methyl phenoxy acetate is reasonable. KEYWORDS: ARVI, secondary immunodeficiency, interferon, adolescents, outpatient practice, oxyethyl ammonium methyl phenoxy acetate, adaptogen, interferon inducer, fever, asthenia. FOR CITATION: Esaulenko E.V., Novak K.E., Ibrokhimova A.D., Pozdnyakova M.G., Balashov A.L., Noginova E.Yu. Oxyethyl ammonium methyl phenoxy acetate for the outpatient treatment of acute respiratory viral infections. Russian Medical Inquiry. 2023;7(11):718–724 (in Russ.). DOI: 10.32364/2587-6821-2023-7-11-3.