At the moment, the clinical differences between primary acute and reactivation of chronic infection caused by Epstein-Barr virus (EBV) have not been fully studied.The aim is to identify clinical and laboratory differences between primary acute and reactivation of chronic EBV infection in children aged 0—17 years.Materials and methods. A systematic review and meta-analysis of publications was carried out, which were searched through the bibliographic databases PubMed, Cyberleninka, eLibrary, as well as using the Researchgate scientific network. The total number of keyword search results was 1,830 publications, of which 26 were included in the study according to the results of the selection. 1318 cases of active EB infection were subjected to meta-analysis, including 917 cases of acute primary and 401 cases of reactivation.Results. Distinctive signs of primary acute EBV infection are fever, generalized lymphadenopathy, enlargement of cervical lymph nodes, acute tonsillitis, exanthema, excess of ALT reference values, leukocytosis, the presence of atypical mononuclears. With the reactivation of chronic EBV infection, the clinical manifestations are less pronounced, but in 24% of cases the disease is accompanied by the development of interstitial pneumonia. Characteristic signs are hypertrophy of the lymphoepithelial pharyngeal ring and thymomegaly, not described in primary acute infection.Conclusion. The revealed clinical and laboratory differences between primary acute and reactivation of chronic EBV infection in children aged 0—17 years can be used for differential diagnosis of these conditions.