To evaluate prognostic value of complete disappearance of the tumor mass in contrast enhanced computerized tomography after initial treatment, 81 patients with supratentorial malignant astrocytomas (57 anaplastic astrocytomas and 24 glioblastomas) were divided into two groups. All complete response CR patients received the gross total resection (more than 95% resection). Average age of this group was significantly younger than that of noncomplete response patients (38.4 vs. 49.7 years old, p < 0.05; Student t-test). In the complete response group, median survival duration was 58 months, 2-year survival rate was 77%, and 5-year survival rate was 34% compared to 12 months, 29%, and 10%, respectively, in the noncomplete response group. The outcome of CR group was significantly better (p < 0.001; Wilcoxon test). Therefore, complete response at completion of the initial treatment is an important predictor of longer survival. Gross total resection is essential to obtain complete response and thus plays a crucial role in the initial treatment of malignant astrocytomas.