PROTOCOL OUTLINE: Patients with recurrent or progressive supratentorial malignant glioma who are considered appropriate for re-operation will be eligible for either phase of the study. Each patient will have tumor biopsy at study entry, followed by continuous intratumoral infusion of IL13-PE38QQR via 1 or 2 intratumoral catheters, placed within the enhancing portion of the tumor. Infusion rate will be held constant at 540 mL/hr (total). Toxicity will be assessed by clinical neurologic examination and laboratory values. Resection will be performed on Day 15 (6-13 days after end of infusion). Pathologic evidence of tumor necrosis will be assessed. Follow-up assessments will include neurologic examinations and MRI scans. No other anti-tumor treatment will be administered for at least 60 days after resection (except for progressive disease). Patients will be observed until death.