The benefits of endovascular treatment (EVT) on large ischemic infarct core mainly focus on a core size of 70–150 ml. The relationship between EVT and very large ischemic infarct core (>150 ml) is unclear. We herein present an acute stroke patient who achieved functional independence after EVT without postoperative decompressive craniectomy despite very large ischemic infarct core. A 50-year-old Asian male was admitted to our hospital with “sudden disturbance of consciousness with left limb weakness for 11 hours”. The patient had a history of clipping treatment for ruptured aneurysms. After an emergency CTA and CTP, very large ischemic core of 190 ml and a mismatch ratio (Tmax > 6s volume/core volume) of 1.9 were shown in preoperative imaging. EVT was performed, and postoperative strict monitoring was conducted without decompressive craniectomy. The patient was discharged from the hospital on the 16th day, scoring 2 on the modified Rankin scale at a 2-year follow-up. Imaging suggests very large ischemic infarct core; if there is a substantial mismatch between major functional areas (large ischemic penumbra) and the patient is relatively young, aggressive EVT may be beneficial.