Background/Aim: High-grade gliomas (HGG) consist of anaplastic oligoastrocytomas, anaplastic oligo-dendrogliomas, anaplastic astrocytomas and glioblastoma multiforme. The present study aimed to evaluate TNF-alpha -308 G>A polymorphism in a Turkish population. Patients and Methods: This was a prospective case-control study that included 45 patients with HGG and 49 healthy individuals. All patients were operated for intracranial tumors and the pathology results consist of high grade (Grade3 and 4) glial tumors. Results: No significant differences were found between the HGG and control groups in terms of the median age (p=0.898). There were no significant differences with regard to gender (p=0.577). The TNF genotype frequency comparison between patients and controls was not statistically significant (p=0.598). Conclusion: TNF genotype frequency comparison between the patients and controls was not statistically significant in the Turkish population tested. However, further studies are needed to evaluate the genotype and phenotype correlations in large cohorts of various ethnicities.