The role of the Epstein—Barr virus (EBV) in the development of inflammatory processes in the gastric mucous membrane (MM) and the influence of the combined infection with EBV and Helicobacter pylori (H.p) on the formation of pathological changes in the upper gastrointestinal tract of the children remain to be clarified. Aim — the objective of the present study was to elucidate the peculiar features of the endoscopically visualized changes in the mucous membrane of the upper gastrointestinal tract of the children presenting with Helicobacter pylori and Epstein—Barr virus co-infection. Material and methods. We have undertaken the analysis of the endoscopically visualized changes in the mucous membrane of the upper gastrointestinal tract of 145 children at the mean age of 10.1±0.3 years wit the use of the polymerase chain reaction (PCR) for the identification of H.p and EBV DNAs in MM biopsy samples obtained from the fundal and antral sections of the stomach. Results. DNA of H.p. was detected in gastric MM of 65 (44.8%) patients of the 145 ones included in the study while DNA of EBV was found in 76 (52.4%) patients. The combination of H.p.+/ EBV+ was documented in 41 (28,3%) patients, H.p. +/ EBV− — in 24 (16,6%), H.p.–/EBV+ — in 35 (24,1%), and H.p. –/ EBV– — in 45 (31%) children . The concurrent infection with H.p. and EBV in the children was associated with more severe endoscopically visualized changes in gastric mucosa the upper gastrointestinal tract than in the patients presenting with isolated infection by either pathogen. It is concluded that further studies of both pathogens are needed for the better understanding of the mechanisms underlying the formation of serious lesions in the mucous membrane of the stomach developing in the children in the association with Helicobacter pylori and EBV virus infections.