Resection of the T1 contrast-enhancing portion of glioblastoma multiforme (GBM) has been shown to increase patient survival, although whether GBM resection beyond these boundaries has an additional survival benefit is not clear. In this study, we examined the effect of resecting the enhancement and a margin of brain tissue surrounding the enhancement in patients with GBM of the temporal lobe. We identified 32 consecutive patients with temporal lobe GBM who underwent initial resection between 2012 and 2015. Progression-free survival (PFS) and overall survival (OS) were analyzed based on the following categories: subtotal resection (STR; <99% of contrast enhancement removed), gross total resection (GTR; 100% of T1 contrast enhancement removed), and supramaximal resection (SMR; removal of T1 contrast enhancement plus removal of at least 1 cm of brain tissue surrounding the enhancement). Patients undergoing SMR demonstrated a substantially improved median PFS (15 months) compared with those undergoing GTR (7 months) or those undergoing STR (6 months) (P < 0.003). A median OS advantage was also present in the SMR group (24 months) compared with the GTR (11 months) and STR (9 months) groups (P < 0.004). SMR significantly improved PFS (hazard ratio HR, 0.093; 95% confidence interval CI, 0.01–0.89; P = 0.039) and OS (HR, 0.169; 95% CI, 0.05–0.57; P < 0.004) when controlling for other variables. The complication rates did not differ among the resection groups (P = 0.66). Achieving SMR substantially improved survival in patients with temporal lobe GBM compared with GTR of the enhancement alone. •This is a retrospective series of 32 patients who underwent resection of temporal lobe glioblastoma multiforme comparing subtotal resection, gross total resection, and supramaximal resection (SMR).•Significantly improved progression-free survival was seen with SMR (P = 0.039).•Significantly improved overall survival was seen with SMR (P < 0.004).•Complication rates did not differ among the 3 resection groups (P = 0.66).