Endovascular embolization of the middle meningeal artery (MMA) has been reported as an effective method for treating chronic subdural hematoma (CSDH); however, its preventive effect on CSDH following craniotomy is unknown. We present a case in which MMA embolization was ineffective in preventing CSDH following craniotomy. A 56-year-old man who complained of diplopia was diagnosed with sphenoid ridge meningioma with a 3-cm diameter. MMA embolization prior to the operation and total surgical removal of the tumor were performed. Two months postoperatively, the patient complained of headache and hemiparesis of the left side. CSDH with a 15-mm thickness and a midline shift was observed. MMA embolization before inflammation may not play a role in preventing CSDH development because MMA embolization is considered effective in CSDH because it is associated with the blood supply of neovessels that are newly formed due to inflammation. Therefore, MMA embolization might not be effective in preventing the occurrence of CSDH following craniotomy.