OBJECTIVE. Determination of morphological and molecular genetic specifics in gemistocytic astrocytomas (GA). MATERIAL AND METHODS. A retrospective and prospective analysis of clinical characteristics, as well as of morphological and molecular genetic features, was performed on 21 patients with the diagnosis of GA. The study included patients over the age of 18 with supratentorial localization of the tumor. The patients were aged from 19 to 56, the median age being 33 years. The number of males was 10. Fragments of tumor tissue obtained during surgery were subjected to histological, immunohistochemical and, in 42,9% of cases, molecular genetic studies. Histological diagnosis was made in accordance with the classification of tumors of the cNS WHo (2016) and the AFIP atlas (2007). By real-time PcR method was used to determine the level of expression of the following genes: TP, VEGF, PDGFRA, p-tubulin, MGMT, c-kit, ERcc1, as well as the presence of a mutation in IDH1/IDH2 genes and co-deletion of 1p19q. RESULTS. The first clinical manifestations of the disease in the vast majority of cases were epileptic and hypertensive syndromes. The tumor most often affected several lobes of the brain (38.1%). Magnetic resonance imaging (MRI) of the brain showed mainly focal accumulation of the contrast medium in 84.6% of patients (out of 13 patients). In GA GIII, vascular proliferation was significantly more frequent than in GA GII (93,3% and 66,7%, respectively). Proliferation of endothelium was detected only in GA GIII (73,3%). Micronecrosis occurred only in 2 patients out of 21 (both GA GIII). The Ki-67> 5% proliferative activity index corresponded to the medium and high levels of vascular endothelial growth factor (VEGF) gene expression except one case (85,7%). The low level of proliferative activity index (Ki-67 <5%) corresponded to the low level of VEGF gene exspresion. A high level of thymidine phosphorylase (TP) gene expression was found only in patients with anaplastic variant of GA, whereas the middle level of expression was observed in both GA GII (with Ki-67 <5%) and GA GIII (Ki-67 >5%). The relationship between the level of expression of PDGFRA and Ki-67 was not established for this sample. coNcLUSioN. In 15 patients out of 21, the morphological, immunohistochemical, and molecular genetic traits were characteristic of the anaplastic variant of GA (GIII). And this group of patients needs complex treatment. The results of molecular genetic research can precise the prognosis of the disease and the choice of the chemotherapeutic tactics.