The article gives the study results for epidemiology, clinical and laboratory data of infectious mononucleosis (IM) of herpes virus etiology in children. The level of disease occurrence ranges during a year from 3.47% to 16.43%, with the highest rate in autumn-winter period (11.5–16.43%). The children up to 6 year old 83.14% suffer from IM as a rule. Clinical manifestation of IM involve fever 96.4%, lacunar tonsillitis 79.5%, lymphadenopathy 17.14%, hepatolienal syndrome 96.4%. At the same time, atypical mononuclear cells were found only in 48.2% of children. 55.42% cases of infectious mononucleosis were caused by a combination of pathogens (VEB and CMV). In isolation, the Epstein–Barr virus was detected in 31.32% of children, and the cytomegalovirus in 10.84%.
