Few patients with glioblastoma multiforme survive more than 5 years. To identify the factors associated with long-term survival, patients with primary supratentorial glioblastoma multiforme diagnosed between 1969 and 1985 were identified from our computer data base. Twenty-two (5%) of the 449 patients identified survived at least 5 years after surgical diagnosis. There were 12 female and 10 male patients, with a mean age of 39.2 years (range, 15 to 63 yr). Twenty patients had a subtotal resection, and 2 had a gross total resection. The median duration of survival was 9.4 years. As of August 1, 1992, 10 patients were alive 5.2 to 13.6 years after diagnosis, and 1 patient was lost to follow-up after 9.4 years. Ten patients died from their tumors; 2 patients with stable tumors died, 1 from a ruptured intracranial aneurysm and 1 from erythromycin-induced hepatitis. Unusual sequelae were noted in irradiated areas in several cases. One patient had a scalp sarcoma and a basal cell carcinoma, and three patients had strokes; each of these events occurred more than 5 years after diagnosis. We conclude that among patients with glioblastoma multiforme, long-term survival is most likely for those who have a long disease-free interval after the initial diagnosis and receive multimodal therapy, including aggressive tumor removal. Other factors associated with long-term survival were younger age and high Karnofsky scores.