A total of 26 patients (6 with anaplastic astrocytoma; 20 with glioblastoma) were treated with crisnatol mesylate. All patients had residual or progressive disease following surgery and standard radiotherapy; nine patients had prior chemotherapy. Crisnatol was administered as a 72-hour infusion every 21 days at a starting dose of 2250 mg/m2. Two patients who had not received prior chemotherapy achieved a complete response and remain in continuous complete remission over seven and six years, respectively, post-diagnosis. Two other patients remained stable on crisnatol for 10 months before disease progression. One patient with mixed oligodendroglioma/glioblastoma progressed after 12 months on crisnatol. He survives at 7 years post-diagnosis, with Karnofsky Performance Status of 60 following other therapies. One patient with anaplastic astrocytoma stopped treatment by request after 10 months and remains stable 64 months post diagnosis. Seventeen evaluable patients, including nine patients with prior chemotherapy, progressed after 2-9 courses of therapy. Median survival is 9.25 months, with a one year survival rate of 30% and 2 years survival rate of 17%. Neurotoxicity was acute and dose-limiting. Side effects were tolerable and limited to duration of infusion. Two complete, long-lasting responses to crisnatol mesylate in patients with progressive malignant glioma are encouraging results and warrant further investigation.