Introduction. The role of disturbance of the intestinal microbiota in the development of diseases of infectious genesis and the possibility of using probiotics as an immunomodulatory agent are confirmed by the evidence base of numerous studies.Purpose. To study the results of using a multi-strain immunoprobiotic from the first days of acute respiratory infection as an emergency prevention, for the purpose of reducing the duration and severity of the disease.Materials and methods.Children from 2 to 10 years old took part in the clinical observation: the main group (45 children) received a multi-strain immunoprobiotic in accordance with the instructions for use for 1 week, starting from the 1–2 day of acute respiratory infection and the comparison group (37 children) who did not receive an immunoprobiotic.Results and discussion. As a result of the study, the effectiveness and safety of the use of an immuno-probiotic in children of preschool and primary school age, when prescribed from the first days of acute respiratory infection, and its positive effect on the course of the disease were shown. The duration of the disease in patients receiving the immunoprobiotic was statistically significantly less, and the severity of the disease was milder than in the comparison group. The incidence of repeated respiratory infections during one month after discontinuation in the main observation group was 3.1 times lower than in the comparison group. At the end of the experiment, statistically significantly higher levels of leukocytes, eosinophils, monocytes and the absolute number of lymphocytes were revealed in the comparison group that did not receive the immunoprobiotic.Conclusions. The obtained results allowed to substantiate the use of a multi-strain immuno-probiotic as a non-specific immunomodulatory agent for emergency prevention when prescribed from the first days of a respiratory infection for the purpose to reduce the duration and severity of the disease.