Background: Central nervous system tumors (CNS) are the second most common malignancies in childhood. Inflammation and changes in nutritional status play an important role and can be used as prognostic markers. Thus, this study aimed to evaluate the predictive ability of nutritional status and inflammatory markers on overall survival (OS) of pediatric patients with CNS. Methods: In this retrospective cohort study, 103 patients were followed for 1, 3, and 5 years. Clinical, anthropometric, and hematological data were collected. Body mass index for age (BMI/A), neutrophil-to-lymphocyte ratio (NLR) and systemic inflammation response index (SIRI) were calculated. OS curves were calculated using the Kaplan Meier method and evaluated using the Log-Rank test. The Cox proportional hazards model was performed to identify independent variables associated with prognostic factors, generating hazard ratios (HR) and 95% confidence intervals (CI). Results: Nutritional status did not significantly affect OS. However, patients with NLR ≥ 2.18 and SIRI ≥ 1249.18 had significantly lower OS in the three periods evaluated. However, only treatment with exclusive radiotherapy or chemotherapy (RT or CT) and high NLR were identified as independent prognostic factors for worse OS. Treatment (RT or CT) was an independent prognostic factor for OS at 1 year (HR: 12.76; 95%CI 1.73-94.12), 3 years (HR: 16.22; 95%CI 2.19-120.06), and 5 years (HR: 16.2295%CI 2.19-120.07) while NLR was a prognostic factor only at 3 years and 5 years (HR: 1.94; 95%CI 1.02-3.69). Conclusion: High pretreatment NLR was shown to be an independent prognostic factor for OS in pediatric patients with CNS.