Introduction: Lemierre’s syndrome (LS) is a rare but serious infectious emergency. It can be life threatening. It is a sepsis difficult to recognize and most often due to Fusobacterium necrophorum. The purpose of this case report was to discuss the diagnosis and treatment of Lemierre syndrome in children. Observation: A three-year-old child consulted for rhinopharyngitis complicated by an abscessed cervical adenophlegmon. The symptomatology had been evolving for 7 days with a notion of self-medication. The blood cell count showed hyperleukocytosis at 14.06.10<sup>3</sup> elements/mm<sup>3</sup>, anemia at 8.2.10<sup>6</sup> elements/mm<sup>3</sup>, and platelets at 102.10<sup>3</sup> elements/mm<sup>3</sup>. CRP was 258.5 mg/dL. HIV serology was negative. Bacteriological culture of the biological fluids collected (abscess pus, blood and joint fluid) was sterile. The CT scan revealed a collection of abscesses in the right sub-angulo-mandibular region. It was associated with thrombophlebitis of the internal jugular vein, as well as pulmonary and joint infections. The diagnosis of Lemierre syndrome was done. Cervicotomy allowed drainage of the abscess. A triple parenteral antibiotic therapy (Ceftriaxone, Metronidazole, Gentamycin) with per-os relay by Amoxicillin + Clavulanic Acid allowed to obtain the cure in one month of treatement without complications. Conclusion: LS is difficult to diagnose due to its non-specific clinical presentation and low incidence. Early clinical and imaging diagnosis guarantees a good outcome by allowing adequate treatment.