Extended survival of 3 or more years is rare in patients with glioblastoma (GBM) but is becoming more common. Clinical outcome has not been well studied. We reviewed GBM patients at Memorial Sloan-Kettering Cancer Center between 2001 and 2003 who were seen for two or more visits. Patient characteristics and long-term clinical outcomes were reviewed for patients who had survived 3 or more years following diagnosis. Thirty-nine (11%) of 352 GBM patients were identified as long-term survivors. Median survival was 9.15 years (range: 3-18 years). Median age was 47 years (range: 16-69); 13% were 65 years or older. Median KPS was 90 (range: 50-100). One long-term survivor underwent biopsy alone; 19 patients each had either complete or subtotal resection. All received focal radiotherapy (RT) with a median dose of 5940 cGy; 18% received concurrent temozolomide. Adjuvant chemotherapy was administered to 35 (90%). Twelve patients (31%) remained in continuous remission. Twenty-seven had tumor progression a median of 29.2 months after diagnosis (range: 1.2-167 months); 18 had multiple relapses. Median KPS at last follow-up was 70 (range: 40-100); 85% of long-term survivors had at least one significant neurologic deficit. Eleven (28%) had clinically significant RT-induced leukoencephalopathy, 9 (23%) developed RT necrosis and 9 (23%) treatment-related strokes. Treatment-related complications occurred a median of 2.7 years from diagnosis (range: 0.9-11.5 years). Long-term survivors remain rare, but are found across all age groups despite multiple recurrences; clinically significant delayed complications of treatment are common.