OBJECTIVES: This study was to assess management outcome of patient undergoing decompressive craniectomy for space-occupying cerebral infarction refractory to medical treatment and to identify risk factors associated with unfavorable outcomes. PATIENTS AND METHODS: Between January 1999 and June 2004, total 20 patients were analyzed. The preoperative consciousness was rated using Glasgow Coma Scale (GCS). The clinical outcome was rated using Glasgow Outcome Scale (GOS) at 3 months follow up and divided into 2 groups;favorable outcome group (GOS> or =3) and unfavorable outcome group (GOS<3). The prognostic factors were analyzed multivariately. RESULTS: Fourteen patients were men and six patients were women (mean age, 58.7 yrs). Seventeen patients had right hemispheric infarction, and three patients had left hemispheric infarction. 16 patients had only middle cerebral artery (MCA) infarction, and 2 patients had combined anterior cerebral artery (ACA) or posterior cerebral artery (PCA) infarction respectively. Eleven patients showed anisocoria preoperatively. The mean time interval between symptom onset of infarction and operation was 61.5 hrs. 8 patients showed favorable outcome, and 12 patients showed unfavorable outcome. CONCLUSIONS: The existence of preoperative anisocoria and low preoperative GCS score were statistically significant prognostic factor related to unfavorable outcome.