Preserving the health of the younger generation is a priority multidisciplinary task. For a more comprehensive and individual assessment of the functioning of the child's body against the background of acute viral infections, a technique for determining the quality of life based on subjective perception was used, on the basis of which patients are classified into the first or second classes of quality of life. The paper examines the interrelationships of health, quality of life and mental development of preschool children with acute respiratory infections being treated in the pediatric department. Some children were found to have a reduced quality of life, not only in the group of children with acute respiratory infections, but also in the group of healthy children. There were significantly more patients with grade 2 quality of life in the main group. According to the results of correlation analysis using Spearmanʼs rank correlation coefficient, it was found that the quality of life is interrelated with psycho-emotional and the intellectual development of the child. Based on the study of the quality of life of patients in the pediatric department, it is possible to implement an individual approach to assessing the condition of the child as a whole and against the background of the disease, for high-quality further treatment and monitoring, for the organization of preventive measures.