CT scans of 12 patients who underwent resection of recurrent malignant astrocytoma and who had a radiographically documented second tumor recurrence were studied. Second tumor recurrence was histologically verified in four patients. Eight of 12 second recurrences were no more than 2.0 cm from the contrast-enhancing margin of the first recurrence. The remaining four patients had tumor recurrence within 2.2, 4.6, 5.1 and 6.9 cm of the enhancing margin of the first tumor recurrence. Peritumoral edema at the time of initial recurrence had no relationship to the patterns of second recurrence. It is concluded that patients who undergo reoperation for recurrent malignant astrocytoma are still primarily at risk for local tumor failure, as opposed to diffuse dissemination of disease throughout the brain.