Perinatal inflammatory retinal diseases and intrauterine retinal maldevelopments are mistaken for retinoblastoma as often as in 8-16% of cases. Aim — to analyze the infectious status in children with retinoblastoma and pseudoretinoblastoma at different ages. Material and methods. A total of 47 retinoblastoma suspects aged 4-69 months were enrolled. Pseudoretinoblastoma (inflammatory retinal diseases and intrauterine maldevelopments of the retina) was detected in 14 children (group 1), retinoblastoma — in 33 children (group 2). In each group, two subgroups were identified: «a» — children under 12 months of age (1a — 5 patients, 2a — 10 patients) and «b»— children over 12 months of age (1b — 9 patients, 2b — 23 patients). Their blood sera were examined for antibodies to herpes simplex virus types 1 and 2, cytomegalovirus, Epstein—Barr virus, toxoplasma, toxocara, chlamydia, and mycoplasma (enzyme-linked immunosorbent assay). Results. According to serological screening, all patients from group 1a (children under 12 months of age with pseudoretinoblastoma), in contrast to other groups, were infected perinatally with cytomegalovirus infection. All 47 patients were seronegative to toxoplasma. Toxocara infection was identified in children over 12 months of age: in 3 out of 9 patients with pseudoretinoblastoma and in 2 out of 23 patients with retinoblastoma (p>0.05). Markers of Epstein-Barr viral activity were detected only in 3 retinoblastoma children over 12 months of age. Conclusion. The results suggest that cytomegalovirus infection plays the leading role in the development of perinatal eye pathology, which, in infants, is clinically similar to retinoblastoma. In children over 12 months of age we found no serological signs that could be regarded as specific of either retinoblastoma, or pseudoretinoblastoma. The only thing worth paying attention to is the activation of Epstein-Barr virus infection in children over 12 months of age with retinoblastoma.