A 15-year-old boy presented with signs of sepsis and a history of sore throat, fevers and shortness of breath. Full examination revealed an erythematous oropharynx and mild tonsillar swelling. He rapidly deteriorated requiring admission to intensive care. Blood cultures grew Fusobacterium necrophorum and an ultrasound scan performed for left neck tenderness confirmed internal jugular vein thrombosis. He was diagnosed with Lemierre's syndrome. This condition results from pharyngitis or tonsillitis with bacterial spread to the lateral pharyngeal space. Internal jugular vein thrombosis ensues with septic emboli and metastatic infections that most frequently involve the lungs. Although increasing in incidence, diagnosis is often delayed. We discuss why and describe its clinical presentation, investigations of choice and treatment strategies.