A 74-year-old man presented with fever, sore throat and neck pain 11 days after extraction of his tooth. At presentation, his neck was swollen along the left sternocleidomastoid muscle. Contrast-enhanced CT showed thrombosis of the left internal jugular vein and multiple septic emboli in the lungs. Contrast-enhanced MRI and CT showed cavernous sinus thrombosis. On the basis of these findings, we made the diagnosis of Lemierre’s syndrome. The patient was successfully treated with intravenous antibiotics, heparin and warfarin. A rapid diagnosis of Lemierre’s syndrome is essential, because this syndrome can prove fatal in case of a diagnostic delay.