Fifty-eight patients harboring recurrent malignant brain tumors were evaluated. CCNU (110 mg/m2) was administered on Day 1, procarbazine (60 mg/m2) was administered daily for 14 days beginning on Day 8, and vincristine (1.4 mg/m2) was administered on Days 8 and 29 of each 6-week cycle of therapy. Therapy was continued until tumor progression was documented. Before each course, a neurologic examination was performed and radionuclide and computerized tomographic scans were obtained. Response and progression were defined as improvement or deterioration, respectively, in at least two of the three tests. Of the 46 patients harboring recurrent malignant gliomas, 12 (26%) responded to therapy, 18 (39%) had tumor progression, and 16 (35%) had disease stability. Nineteen of the 46 patients were not previously treated with another form of chemotherapy: eight (42%) responded to therapy, eight (42%) had disease stability, and only three (16%) had early tumor progression. The median time to tumor progression was 26 weeks for patients responding to therapy or having disease stability. Approximately 30% of the patients were alive without evidence of tumor progression at 1 year. Evaluated by time to tumor progression and rate of tumor response or stabilization, this combination was similar to the BCNU-5-fluorouracil combination used for patients harboring recurrent malignant glioma.