The prognostic relevance of epilepsy at glioblastoma (GBMs) onset is still under debate. In this study, we analyzed the value of epilepsy and other prognostic factors on GBMs survival. We retrospectively analyzed the clinical, radiological, surgical and histological data in 139 GBMs. Seizures were the presenting symptoms in 50 patients out of 139 (35.9%). 123 patients (88%) were treated with craniotomy and tumor resection while 16 (12%) with biopsy. The median overall survival was 9.9 months from surgery. At univariable Cox regression, the factors that significantly improved survival were age less than 65 years (P = 0.0015), focal without impairment of consciousness seizures at presentation (P = 0.043), complete surgical resection (P < 0.001), pre-operative Karnofsky performance status (KPS) > 70 (P = 0.015), frontal location (P < 0.001), radiotherapy (XRT) plus concomitant and adjuvant TMZ (P < 0.001). A multivariable Cox regression showed that the complete surgical resection (P < 0.0001), age less than 65 years (P = 0.008), frontal location (P = 0.0001) and XRT adjuvant temozolomide (TMZ) (P < 0.0001) were independent factors on longer survival. In our series epilepsy at presentation is not an independent prognostic factor for longer survival in GBM patients. Only in the subgroup of patients with focal seizures without impairment of consciousness, epilepsy was associated with an increased significant overall survival at univariate analysis (P = 0.043). Main independent factors for relatively favorable GBMs outcome are complete tumor resection plus combined XRT-TMZ, frontal location and patient age below 65 years old.