Limited data are available concerning the outcome of patients with atypical and malignant meningiomas. We therefore analyzed the outcome of seventeen patients with meningiomas (9 atypical; 8 malignant) at Thomas Jefferson University Hospital between 1973 and 1996. Strict adherence to the 1993 WHO criteria for the typing of CNS tumors was maintained. The median potential follow-up period for all patients was 87 months. The age at diagnosis ranged from 22 to 72 (mean 51.8 years). There were 5 males and 12 females. The mean tumor diameter was 4.45 cm. Of the 16 cases where the extent of surgical resection was known, 4 were partial and 12 were complete resections. Six patients (35%) had dural or cortical invasion by tumor. Fifteen patients received postoperative megavoltage photon irradiation (mean 61 Gy). One of these fifteen pts. received an additional 20 Gy with Au-198 implantation and 1 received post-radiation chemotherapy for recurrent disease. The overall survival rate for all patients at 5 and 10 years were 87% and 58% respectively. The 5- and 10-year survival rates for atypical meningiomas were 87% and 58%; for malignant meningiomas the survival rates were 60% and 60% respectively. Five patients (30%) have died. Three of these 5 patients initially received less than 54 Gy to the tumor bed and have died of recurrent disease. Local disease progression was documented in 11 patients (65%) after surgery and in 3 patients (18%) after radiation. There was an improvement in performance status in 3 (18%) patients with a decline and no change seen in 1 (6%) and 13 (77%) respectively after receiving radiation. There appeared to be no difference in survival in patients as a function of dural or cortical invasion. Long term survival is possible for patients with atypical and malignant meningiomas treated with surgery and post-operative radiation. We are unable to distinguish a difference in outcome between these two pathological entities. Dural and cortical invasion were not associated with a decrease in survival. In addition, improved tumor control and survival may be associated with increased radiation dose.