Purpose <p>Although there are consistent guidelines of standardised glioblastoma patient care, there may be variation in treatments delivered due to differences in patient characteristics or adherence to guidelines across centres. This study explores the variation in treatments for glioblastoma patients across centres in a comprehensive multi-year brain tumour patient cohort in England.</p> Methods <p>We analysed data from the Gliocova project that contains over 50,000 adult brain tumour patients diagnosed between 2013 and 2018 in England. We selected a glioblastoma patient cohort and explored treatment rates, systemic predictors of treatment, variation in treatment across surgical centres and survival rates for different treatment groups.</p> Results <p>We analysed data from 11 359 patients with a histological diagnosis of GBM. Almost 80% of glioblastoma patients received at least some treatment after brain surgery, with 40% receiving the guideline recommended aggressive treatment (47% in the under-70s cohort). Age, sex, deprivation status, comorbidities, surgery type (resection versus biopsy) and ethnicity were identified as systemic predictors of receipt of post-operative treatment. There was also variation in receipt of post-operative treatment (64%-86%) and receipt of aggressive treatment (16%-65%) across centres. Patients receiving aggressive treatment had highest survival (15.6 months); in patients receiving any post operative treatment survival was 12.5 months and in patients receiving surgery only survival was 2.5 months.</p> Conclusion <p>22% of glioblastoma patients undergoing surgery receive no further treatment and there is variation in post-surgical treatment both at centre and individual patient level. We suggest that centres should measure and report rates of no further treatment as part of standard clinical governance.</p>