Lemierre's syndrome is characterized by a septic inflammatory condition involving internal jugular veins and is frequently caused by an oropharyngeal infection. While it usually results in pulmonary embolization, this case demonstrates a rare but significant cerebral embolization. The case involves an 18-year-old woman who experienced left-sided neck swelling and difficulty swallowing five days after a tooth extraction, an uncommon trigger. Her symptoms progressed to a headache, localized seizures, and mental state changes. Upon hospital admission, she was febrile, had noticeable neck swelling, and a reduced Glasgow Coma Scale score. CT scans of her neck and her brain revealed an occurrence of septic emboli, indicating a septic thrombophlebitis that affected the internal jugular vein. As surgical intervention is rarely required in such cases, her treatment involved antibiotics and symptom management.