Massive ischemic stroke with a severe edema of a damaged lesion and fatal dislocation syndrome develops in 7% of patients with the dissection of the inner carotid artery. Decompressive trepanation (DCT) may be used in case of malignant course of massive stroke with the development of lateral dislocation more than 7 mm on the level of the pellucid septum in the first 48h from disease onset or high risk of fatal outcome. A clinical case of massive ischemic stroke caused by the dissection of an intracranial area of the inner carotid artery in a young patient is presented. The disease was complicated by the development of life threatening dislocation syndrome. DCT performed before the development of the decompensation of dislocation syndrome contributed to the favorable outcome (the preservation of life) of disease and decreased the functional deficit so that the patient can move independently and help himself in daily activities.