In patients diagnosed with glioblastoma (GBM), minimal data exist on the pathway to presentation and the impact of symptoms on survival outcomes. This study aims to detail the symptoms that occur at time of initial presentation, the response to subsequent intervention, and the factors that predict survival in patients managed for GBM. A retrospective audit was performed from established prospective databases in patients managed consecutively with radiation therapy (RT) for GBM between 2016 and 2019. The major endpoint was median overall survival (mOS). Analysis was performed to determine associations with clinical factors including presenting symptom, performance status, tumour site and extent of resection. The level of carer support and objective perception of carer mastery was also assessed. Overall, 182 patients with GBM were eligible for analysis. The majority of patients presented directly to Emergency (52%), with the most common initial presenting symptom being personality change in 23% of patients. The primary symptoms resolved pre-operatively in 47% of patients, with 9% having worse symptoms postoperatively. The mOS was 16.5 months (95% CI: 14.5-18.5). ECOG Scores 0-1 were associated with improved mOS at both initial ECOG (P < 0.001) and ECOG at 6 months (P = 0.006). Recognised Carer Mastery (P = 0.007) but not presence of carer (P = 0.35) was associated with improved mOS. In patients with GBM initial presenting symptoms, level of performance status and role of carer influence clinical outcomes and survival. These findings can assist to guide clinicians and supportive care services to optimise future patient care.