Objective. In the structure of oncological diseases of childhood, blood diseases occupy a leading position (40%). According to some researchers, the prevalence of mental disorders among patients with oncohematological pathology is very high, regardless of the age of patients. The aim of this work was to identify clinical/dynamic and typological characteristics of mental disorders in children with hematological malignancies as well as the factors predisposing to these disorders. Material and methods. The study involved 96 children (63 boys and 33 girls), aged 3-12 years, with hematological malignancies (acute lymphoblastic leukemia, acute myeloid leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma). Results and conclusion. Mental disorders were presented with a wide range of violations, including the endogenous pathology (8 children), a mild degree of mental retardation (n=2), adjustment disorders (n=86). Adjustment (adaptation) disorders included andiety, phobic and depressive reactions. The appearance, form and severity of disorders were influenced by a range of factors, which had a different contribution to the process. Family history, premorbid personality traits, interpersonal relationships within the family and the type of education seem to be less important compared to the age of the patients that determined the preferred range of disorders, forming the leading psichogenic symptoms.