Objective: Glioblastoma Multiforme (GBM) is the most common primary malignant brain tumor in adults. Optimaltreatment is adjuvant concomitant chemoradiotherapy following the widest possible surgical resection (maximum saferesection) followed by adjuvant chemotherapy. However, the geriatric group is not treated optimally. Recent studies haveshown that optimal treatment benefits in the older group, similar to those in younger patients.We aimed to investigatethe effect of optimal treatment on survival in patients 65 years of age and older with GBM. Methods: In Pamukkale University Medical Oncology Clinic, the files of 71 patients with a pathological diagnosis of GBMbetween 2010 and 2018 were retrospectively evaluated.Demographic and clinicopathological characteristics of thepatients were recorded from the file. Results: Of the 71 patients evaluated, 25 (35.2%) were 65 and over, 46 (64.8%) were under 65 years old. Of the twenty five patients, 11 (44%) were male and 14 (56%) were female. Median follow-up time was 16.2 months (12.4-19.9) andmedian overall survival time was 12.5 months (10.4-14.7) in all patient groups. The median overall survival of patientsunder the age of 65 years was 15.1 months (12.6-17.6 months), and patients aged 65 and over were 8.6 months (7.9-9.3months) (p <0.001). The median overall survival was 8.9 months (8.4-9.4 months) in patients 65 years and older whoreceived optimal treatment, while the median overall survival was 7.9 months (3.4-12.4 months) in patients who did not(p:0.048). Conclusion: The median overall survival time of patients 65 years and older who received optimal therapy wassignificantly longer than those who did not. It has been observed that survival outcomes are improved when elderlypatients with good performance can receive optimal treatment like younger patients.