Carotid endarterectomy (CEA) and carotid artery stenting (CAS) for internal carotid artery (ICA) stenosis have specific risks. Therefore, the accurate evaluation and management of each risk factor are important, especially for patients who are at high risk for both CEA and CAS. We report the case of a 77-year-old man with right ICA stenosis that progressed despite optimal medical treatment. In addition, he had several risk factors for both CEA and CAS, including previous cervical radiation therapy, contralateral ICA occlusion, chronic kidney insufficiency, and severe aortic valve stenosis. CEA was performed with priority given to aortic valve stenosis without complications, and the patient was discharged 10 days postoperatively, without neurological sequelae. However, a pericarotid cervical abscess was detected by carotid echo, computed tomography (CT), and magnetic resonance imaging (MRI) 1 month after CEA that required surgical drainage. The infection was thought to be odontogenic because the pathogen was identified as normal oral bacterial flora, and a wound infection was not apparent. Teeth extraction and abscess drainage, in combination with antibiotic therapy, successfully cured the infection without additional complications. Odontogenic cervical abscesses after CEA can occur, especially if the patient is at risk of infection. Therefore, both preoperative and postoperative dental evaluation and management are recommended. As in this case, a cervical abscess can occur without wound infection, and the abscess diagnosis is sometimes difficult from wound inspection alone. Cervical echocardiogram and CT were useful for detecting fluid collection, whereas MRI was useful for qualitatively evaluating the lesion.