Background: Gangliogliomas (GG) represent less than 1% of primary brain tumors in adults. Little is known regarding prognostic features, clinical characteristics or the impact of treatment on patient (pt) outcomes. Methods: In this IRB approved retrospective study, our neuro-oncology longitudinal database was screened for pts with GG from 1992-2012. 67 adult pts (age>18) were identified. Results: 60 pts presented with low grade GG and 7 with anaplastic GG. The median age at diagnosis was 27 years (18-59). 22 pts developed recurrent disease (18 low grade and 4 high grade) with a median time to recurrence of 87 weeks from surgery. 7 of the pts with low grade GG had malignant transformation to a malignant tumor (anaplastic GG or GBM). 22 pts received radiation therapy, 16 at diagnosis. 14 pts received chemotherapy at recurrence. Pts with incomplete resections or higher grade tumors were more likely to receive chemotherapy or radiation. The median overall survival (OS) time for these pts was not reached with a median follow-up time of 4.6 years. The 2-, 5- and 10-year OS were 98%, 87%, and 76%. Factors on univariate analysis that were significantly associated with OS were KPS at presentation (HR 10.1; 95% CI 2.6, 39.1; p = 0.0008), extent of resection (EOR) (biopsy vs gross total; HR 12.1; 95% CI 2.3, 63.6; p = 0.003), histologic grade (Grade 1-2 vs Grade 3-4; HR 0.06; 95% CI 0.01, 0.3; p = 0.0002), and seizure control following surgery (Engel I vs Engel 2-3; HR 0.1; 95% CI 0.01, 0.9; p = 0.02). Factors on univariate analysis that were significantly associated with progression free survival (PFS) were EOR (biopsy vs gross total; HR 4.0; 95% CI 1.4, 11.9; p = 0.01) and histologic grade (Grade 1-2 vs .Grade 3-4; HR 0.3; 95% CI 0.08, 0.8; p = 0.02). On multivariate analysis, EOR is most significant for PFS (p = 0.01), while tumor grade is most significant for OS (p = 0.004). Conclusions: While GG have an excellent prognosis, malignant histological grade, diagnosis with a biopsy only, poor initial KPS, and presence of seizures following surgery could indicate a worse prognosis. The role of chemotherapy and radiation therapy for incompletely resected or inaccessible low grade GG is unclear.