Pediatric oncology, hematology and immunology are subdisciplines of medical science, which study the problems of pediatrics, oncology, neonatology, concerning malignant and nonmalignant tumors in patients of babyhood, childhood and adolescence, and also pathology of blood and blood-forming organ, reactions of child's organism on foreign structures (antigens): mechanisms of these reactions, their manifestations, course and outcome in a norm and pathology. A high level of medical care rendered to children with oncological diseases, diseases of blood and blood-forming organs, immune system in healthcare establishments of the Republic of Belarus is recognized by specialists of leading world medical centers.