The complet obstruction of arteria cerebri media (ACM) or with arteria cerebri anterior (ACA) or arteria cerebri posterior (ACP) is termed as "malignant ACM infarction". This types of infarcts have poor prognosis and the patients generally die because of 'herniation. In this study, we have examined the prognostic factors which might influence the clinical progresşes of 19 patients, who had taken the diagnosis of malignant ACM infarction. During the last year in our clinic the ratio of patients with complete ACM infarction were 7.3 %. The evaluation of the patients clinical state at referral esere made Glasgow comal scale (GCS). Cerebral oedema, midline shift and the size of infarct were determinated by cranial computerized tomography. The functional state of survived patients were evaluated by Barthel index. The patients whose mean GCS at referral were 8 or below have died in 2-4 days time. The cause of deaths was transtentorial hernicıtion. Only three patients of our sample survived (15 %) and their mean Barthel index score was 60 (45-70):The factors effecting the poor prognosis and the importance of early decompression surgery in complete ACM infarcts were discussed in the light of literature knowledge.