Background: Glioblastoma multiforme (GBM) is the most common and aggressive malignant primary brain tumor. Surgery followed of temozolomide administered concurrently with radiation therapy (RT) and followed by adjuvant temozolomide for six cycles significantly improved survival compared with radiation therapy alone in a randomized controlled trial published by Stupp and colleagues. Real world evidence in patients with GBM is scarce in Latin America. Methods: A retrospective study was conducted at the Hospital de Oncología, Centro Médico Nacional Siglo XXI, a referral center in Mexico City. We included histologically confirmed patients with GBM treated in a period from January 2015 to January 2019. Descriptive statistics and Kaplan-Meier method with log-rank were used for analysis. Cox regression was used for multivariate analysis. Results: A total of 184 patients were included, 96 were men (52,2%) and 88 were women (47.8%); median age was 56 years (range 18 - 87). ECOG performance status scale 0-1, and ≥ 2 represented 34.2% and 65.8% of the cohort, respectively. Maximal surgical resection was performed in 172 patients (93%). After surgery or biopsy, 12 patients (6.5%) did not receive any subsequent oncology treatment. Treatment with concomitant RT with TMZ was offered to 156 patients (84.4%) and RT alone to 16 patients (8.7%). The most common RT modality was conventional fractionation (60 Gy in 30 fractions) in 75% of cases. After concurrent therapy, 135 (86.5%) received adjuvant TMZ, of which 53.4% received ≤ 5 cycles and 46.6% received ≥ 6 cycles. The median overall survival of the entire cohort was 20.1 months (95% CI 13.3 - 26.9 months). Survival in patients with adjuvant TMZ was superior versus patients who did not receive complete multimodal treatment (26.3 months vs 10.5 months, p < 0.001). In the multivariate analysis, adjuvant chemotherapy was the only independent factor with statistical significance HR 0.18 (95% CI, 0.08 to 0.41 [p < 0.001]). Conclusions: In this retrospective study our data confirm that receiving adjuvant TMZ treatment is beneficial in prolonging overall survival compared to those who do not receive adjuvant therapy in patients with GBM.