Bronchial artery embolization (BAE) is an effective and minimally invasive procedure for managing massive or medically refractory hemoptysis. Despite its overall safety, BAE can be associated with complications, including nontarget embolization, with cerebral infarction being a rare but severe adverse event. We report a case of posterior circulation infarction, caused by unintended embolization of trisacryl gelatin microspheres via anastomosis between the left bronchial and left subclavian arteries, following BAE in a 45-year-old man with massive hemoptysis. After the BAE, the patient complained of nausea and vomiting. Magnetic resonance imaging (MRI) revealed multifocal bilateral posterior circulation infarctions. The patient was initially treated with aspirin. However, follow-up MRI the next day showed hemorrhagic transformation of the right thalamic infarct along with right lateral intraventricular hemorrhage. Consequently, aspirin was discontinued, and blood pressure was carefully managed. Seven days later, the patient’s symptoms improved without any neurological sequelae. This case highlights the importance of superselective catheterization, meticulous angiographic assessment, and repeat angiography during embolization to minimize neurological complications. Anticoagulation therapy may be beneficial for the management of such complications.