en Brain Tumors Research <strong>Background and Aim:</strong> Glioblastoma (GBM) is the most aggressive primary malignancy of the central nervous system and continues to be associated with dismal survival outcomes despite advances in surgical and adjuvant therapies. In recent years, systemic inflammation has emerged as a potential contributor to tumor progression, prompting growing interest in readily accessible blood-based biomarkers. Among these, the neutrophil-to-lymphocyte ratio (NLR) and platelet-tolymphocyte ratio (PLR) have been proposed as simple and cost-effective prognostic indicators; however, their clinical utility in GBM remains uncertain.<br> <strong>Methods and Materials/Patients:</strong> This observational cohort study included 71 adult patients with histologically confirmed GBM. Pre-treatment hematological parameters were obtained within 24 hours before surgery, including leukocyte subsets and platelet counts, from which NLR and PLR were calculated. Overall survival (OS) was evaluated over a six-month follow-up period. Survival distributions were estimated using the Kaplan&ndash;Meier method, and associations between variables and survival were assessed using Cox proportional hazards models.<br> <strong>Results:</strong> At baseline, patients exhibited a systemic inflammatory profile, reflected by elevated median NLR and PLR values. During follow-up, 39.4% of patients died, with a median OS of 180 days. Despite this inflammatory pattern, neither NLR nor PLR was significantly associated with OS in either univariable or multivariable analyses. Similarly, no meaningful relationships were observed between survival and other hematological parameters or baseline clinical characteristics, including age, sex, and comorbidities. Glioblastoma, Systemic inflammation, NLR, PLR, Prognosis, Peripheral biomarkers 0 0 http://irjns.org/browse.php?a_code=A-10-467-2&slc_lang=en&sid=1 Reza Hatami 100319475328460013135 100319475328460013135 No School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. Seyedeh Elham Norollahi 100319475328460013136 100319475328460013136 No Reproductive Health Research Center, Al-Zahra Hospital, Guilan University of Medical Sciences, Rasht, Iran. Ali Ashraf 100319475328460013137 100319475328460013137 No Clinical Research Development Unit, Poursina Hospital, Guilan University of Medical Sciences, Rasht, Iran. Zahra Abedi 100319475328460013138 100319475328460013138 No Department of Molecular Genetics, To.C., Islamic Azad University, Tonekabon, Iran. Paridokht Karimiyan 100319475328460013139 100319475328460013139 No Department of Pathology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran. Shahrokh Yousefzadeh 100319475328460013140 100319475328460013140 No Guilan Road Trauma Research Center, Trauma Institute, Guilan University of Medical Sciences, Rasht, Iran. Fatemeh Afshar a.a.hormoz333@gmail.com 100319475328460013141 100319475328460013141 No School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran Delaram Nazari 100319475328460013142 0009-0002-4440-6697 No School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Ali Akbar Samadani a.a.hormoz@gmail.com 100319475328460013143 100319475328460013143 Yes Guilan Road Trauma Research Center, Trauma Institute, Guilan University of Medical Sciences, Rasht, Iran