<p>Lemierre syndrome is a systemic suppurative infectious disease caused by septic thrombophlebitis of the internal jugular vein. Because multiple organs can be involved, diagnosis is often challenging, and treatment may be delayed. Cerebral infarction and cavernous sinus thrombosis are rare complications. We describe the case of a 65-year-old man who initially presented with headache and vomiting. Based on cerebrospinal fluid analysis and cranial magnetic resonance imaging, viral infection was first suspected. Despite antiviral therapy, his condition worsened. He developed fever, left ptosis, vision loss in the left eye, dysphagia, water choking, and right hemiparesis. Chest computed tomography revealed a cavity within a partially mass-like shadow in the upper lobe of the right lung. Blood cultures identified anaerobic gram-positive cocci. Magnetic resonance venography revealed left internal jugular vein thrombosis. Brain magnetic resonance imaging showed enhancement in multiple lesions involving the bilateral temporal fossae, para-nasopharyngeal soft tissues, and pterygoid sinuses. There was an abnormal signal in the cavernous sinus soft tissues and cerebral infarction in the left internal capsule. By integrating clinical findings, the patient was diagnosed with Lemierre syndrome. His condition improved with antimicrobial and anticoagulation therapy. Although Lemierre syndrome typically presents with thrombophlebitis and septicemia, this case highlights a rare and atypical manifestation involving the central nervous system. Clinicians should increase awareness of Lemierre syndrome to reduce risks of misdiagnosis and missed diagnosis. Emphasize the diagnostic value of imaging studies in this condition.</p>