The study objective is to present a rare clinical observation, describe a successful 2-stage neurosurgical treatment of a pregnant patient with glioblastoma complicated by acute occlusive hydrocephalus.Materials and methods. A pregnant woman, 36 years (pregnancy 28–29 weeks), was urgently hospitalized with a suspicion for preeclampsia at a multispecialty hospital with a maternity ward. One day prior to hospitalization the patient developed hypertensive syndrome manifesting through headache, nausea, vomiting, depressed consciousness to stupor, then seizures in the extremities with loss of consciousness.Examination had shown malignant paraventricular tumor of the left temporal and parietal lobes accompanied by perifocal edema, brain dislocation, and acute occlusive triventricular hydrocephalus.Results. Treatment included the following stages: 1) emergency endoscopic third ventriculocisternostomy under local anesthesia, 2) premature delivery per cesarean section, 3) microsurgical resection of the brain tumor. Histological examination diagnosed glioblastoma (grade IV). The patient was discharged with minimal neurological deficiency (elements of motor and sensory aphasia) for administration of chemoradiation therapy.Conclusion. Surgical treatment of a patient with glioblastoma and acute occlusive hydrocephalus in the 3rd trimester can be performed safely and effectively for the mother and fetus in 2 stages. Third ventriculocisternostomy under local anesthesia is recommended as a method of cerebrospinal fluid drainage.