Time to maximum concentration (Tmax)-based target mismatch on computed tomography perfusion (CTP) was used to predict radiological and clinical outcomes in patients with acute ischemic stroke (AIS) with anterior circulation large artery occlusion (LVO) selected for endovascular treatment (EVT). Patients with AIS received CTP within 24 hours of starting, followed by EVT. Using Tmax Limits of more than 9.5 seconds and more than 16 seconds, respectively, critically hypoperfused tissue and ischemic core volumes were automatically determined. The difference between Tmax more than 9.5 seconds and Tmax more than 16 seconds volumes and the ratio between Tmax more than 9.5 seconds and Tmax more than 16 seconds volumes were categorized as ischemia penumbra and Tmax mismatch ratio, respectively. At 24 hours, the final infarct volume (FIV) was assessed using non-contrast computed tomography (CT). A positive clinical outcome was defined as a modified Rankin Scale score of 0 to 2 at 90 days. Using multivariable logistic regression, the predictors of FIV and outcome were evaluated. The optimal Tmax volumes for identifying a favorable outcome were outlined using receiver operating curves. There were 393 patients, of whom 298 (74.8%) had effective recanalization, and 258 (65.5%) had a favorable result. All Tmax parameters were independent predictors of FIV and outcome in multivariable analysis. Tmax more than 16 seconds volume was most strongly associated with FIV (beta coefficient=0.596, P<0.001) and favourable outcome (odds ratio [OR]=0.96 per 1 ml increase, 95% CI = 0.95–0.95, P<0.001). With more than 16 seconds of volume, Tmax had the strongest discriminative capacity for a positive result (AUC=0.88, 95% CI=0.842–0.900). A Tmax of more than 16 seconds volume of 67 ml identified participants with the best prognosis (sensitivity=0.91 and specificity=0.73). Tmax target mismatch predicted radiological and clinical outcomes in individuals with AIS undergoing EVT within 24 hours of onset who had LVO.