A 61-year-old male patient had a recurrence of anaplastic astrocytoma after initial chemoradiotherapy. After histologic confirmation of the recurrent tumor, he was treated with intravenous administration of human natural tumor necrosis factor-alpha (TNF alpha). Morphometric analysis of the tumor volumes demonstrated that the tumor continued to regress for 8 months during the course of intravenous TNF alpha therapy, and finally disappeared (total dose of intravenous TNF alpha, 785,000 JRU). The regression of tumor paralleled the neurologic improvement. He has had no signs of recurrence for 2 years. The present experience indicates that at least a certain population of malignant gliomas can be successfully treated by a systemic administration of TNF alpha without a major adverse effect.