Background: M. pneumoniae infection constitutes 20-40% cases in etiological structure of community-acquired pneumonia. This infection occurs in all age groups. The aim of our study was to evaluate the relation between serum level of interleukin (IL-2) and clinical manifestation in children with Mycoplasma’s respiratory tract diseases. Material and methods: The study included 33 children, aged 6 months – 7 years, with pneumonia and wheezing for evaluation of changes of IL-2 in peripheral blood in acute Mycoplasma pneumoniae infection. Levels of Mycoplasma pneumoniae-specific antibodies, the peripheral blood concentrations of IL-2 were determined in serum samples obtained at enrollment from all 33 children that were tested by enzime-linked immunosorbent assay. Results: 21 patients completed study group with Mycoplasma-positive infection and 12 children completed control group – Mycoplasma-negative infection. In Mycoplasma – positive group pulmonary complication was determined more frequently in comparison with the control group. The extrapulmonary complications are also encountered in the first group more frequently than in second. IL-2 levels in children with Mycoplasma-positive bronchopulmonary disease was 31.80 ± 2.26 pg/ml and in Mycoplasma-negative group 39.27 ± 3.17 pg/ml. Conclusion: There was an imbalance of disorders of immune response with significant decreasing levels of IL-2 with association pulmonary and extrapulmonary complication in children with M. pneumoniae infection at the acute phase in our study.