Objective - to reveal the nature of the immune system abnormalities in the different clinical forms of congenital syphilis infection. Tasks - to study the dynamics of immunological parameters (cellular, humoral and phagocytic) in patients with various forms of early congenital syphilis (ECS) and to identify the most informative markers for severity and prognosis of the disease. Material and methods. Immunological monitoring was conducted in 40 infants aged 0 to 1 months with ECS in the acute stage of the disease and after specific therapy. Children with ECS were divided into three groups: group 1: 13 (32.50%) infants with diagnosed manifesting ECS with polymorphic symptoms; group 2: 7 (17.50%) patients with monosymptomatic course of syphilitic infection; group 3: 2 (50.0 %) children with latent ECS. Thirty healthy children, who had perinatal contact with the mother (who received treatment for syphilis) were examined as a control. Conclusion. The changes in the immune system in children with ECS depend on the clinical form of the disease and are most pronounced in patients with severe polysymptomatic course of syphilitic infection. Furthermore, the immune system disorders in this group of children are combined and undergo changes during the disease. The majority of the investigated immunological parameters do not restore to control values after specific therapy in patients with polysymptomatic ECS; this can be considered as a severe, complicated course of syphilitic infection. Infants with the monosymptomatic course of the disease, the immunological parameters recover partially, suggesting a potentially protracted course of the process.