Purpose: Seizures are the most common presenting sign of patients with diffuse glioma. In the current study, we performed a meta-analysis to determine the correlation of seizures at presentation to survival outcomes in adult diffuse glioma, and the possible mechanisms were also discussed. Methods: A comprehensive literature search was performed in PUBMED, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials. The pooled hazard ratio (HR) and corresponding 95% confidence interval (Cl) were used to estimate effects. Heterogeneity among studies and publication bias were also evaluated. Results: 11 studies with 2088 patients were finally included for the current meta-analysis. Seizure-free preoperatively was significantly associated with a poor overall survival in patients with diffuse glioma, the pooled HR was 1.73 (95% CI 1.43-2.08, Z = 5.71, p < 0.001). Subgroup analysis was also performed by tumor grade, the same association was identified in both low-grade glioma (pooled HR 2.49, 95% CI 1.47-4.20, Z = 3.40, p < 0.001) and glioblastoma (pooled HR 1.46, 95% CI 1.27-1.68, Z = 5.24, p < 0.001). A significant correlation of seizure-free with a poor progression-free survival was also identified (pooled HR 1.42, 95% CI 1.06-1.92, Z = 2.33, p = 0.02), although only 3 studies comprising 368 patients were included. Conclusion: The current study determined that seizures at presentation were an independent predictor of better survival outcomes in adult diffuse glioma. It is the first study which provides a comprehensive standardized assessment of the association between seizures at presentation with long-term survival outcomes in patients with diffuse glioma. (C) 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.