Objective: Decompressive craniectomy can reduce mortality in selected patients with stroke and traumatic acute subdural hematoma. This study aimed to explore predictive markers for short-term prognosis and mortality risk in patients who underwent decompressive craniectomy due to traumatic acute subdural hematoma or malignant middle cerebral artery occlusion using clinical, radiological, and routine blood biochemistry findings.Material and Methods: Eleven traumatic acute subdural hematoma patients and 11 stroke patients were included in this study. On admission to hospital, for each patient, age, gender, Glasgow Coma Scale scores, anisocoria, time elapsed for decompressive craniectomy administration, midline shift level, duration of stay in Intensive Care Unit and in hospital, and Glasgow Outcome Scale scores on discharge from hospital and blood biochemistry findings were examined.Results: The Glasgow Outcome Scale score was found 3.5 (2-5) in surviving patients and it was seen that short-term prognosis of patients could be associated with lymphocyte, neutrophil, and platelet count, neutrophil-lymphocyte ratio, and serum C-reactive protein level. However, mortality rate in both groups was found 77.2%, and it was thought that age, leukocyte, monocyte and platelet count, and serum blood urea nitrogen level could be associated with mortality risk.Conclusion: As a result, it could be said that decompressive craniectomy could not reduce mortality risk in both groups. However, it was suggested that lymphocyte, neutrophil, and platelet counts, neutrophil-lymphocyte ratio, and serum C-reactive protein levels could be assumed as markers for short-term prognosis. Furthermore, it was concluded that age, leukocyte, monocyte, and platelet counts, and serum blood urea nitrogen levels could be predictors of mortality risk.