Although the association between optic glioma and neurofibromatosis is well recognized, few studies have systematically compared the outcomes of patients with optic gliomas and neurofibromatosis and patients with optic gliomas without neurofibromatosis. In the present study, patients with optic gliomas and Type 1 neurofibromatosis (NF-1) were compared with patients with optic gliomas without NF-1, with respect to survival, time to tumor progression, and tumor location. Forty-four patients with optic gliomas who were evaluated between 1949 and 1991 were studied retrospectively. Sixteen of 44 patients (36%) met the National Institutes of Health criteria for NF-1. The medical records of all patients were examined, and letters of inquiry were sent to every living patient to ascertain current health statuses. Death certificates were obtained to determine causes of death. Follow-up averaged 7.2 years (10.2 yr for patients with NF-1, 5.4 yr for patients without NF-1). The 5- and 10-year survival rates for patients with optic gliomas and NF-1 were 93 and 81%, respectively. For those patients with optic gliomas who did not have NF-1, 5- and 10-year survival rates were 83 and 76%, respectively. Seventeen patients experienced tumor progression (5 with NF-1, 12 without NF-1). A difference was observed in the mean time to tumor progression (first relapse) between the two groups (mean time with NF-1, 8.37 yr; without NF-1, 2.39 yr [P < 0.01]). However, no significant difference in overall survival, as evaluated by a log-rank test of the respective Kaplan-Meier survival curves, was observed between the two groups. A significant difference in distribution of tumor location between the group with NF-1 and the group without NF-1 was also noted (Fisher's exact test, P = 0.0338), although the number of patients evaluated in this series was too small to determine whether this difference in tumor location influenced relapse rate. We conclude that optic gliomas in patients with neurofibromatosis have a different distribution of location as opposed to those in patients without neurofibromatosis, and, for first relapse, the presence of neurofibromatosis is a significant favorable factor.