Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis is a rare, benign, self-limited condition of unknown etiology. A 16-year-old woman with no relevant clinical history seeks medical attention for fever and cervical adenopathies. In a physical examination the patient is found to be febrile (38.5 C) with multiple bilateral, hard-elastic cervical adenopathies, congestive oropharynx and mild splenomegaly with no other relevant pathological findings. The laboratory examination shows signs of pancytopenia and an increase in the erythrocyte sedimentation rate, Β2-microglobulin, transaminases and lactate dehydrogenase. Several serological tests are carried out with negative results except for immunoglobulin G for parvovirus, which is positive. A computerized axial tomography scan of head, neck, thorax, abdomen and pelvis shows bilateral lateral cervical adenomegalies (the largest with a size of 15 mm) and bilateral axillary adenomega- lies of less than 10 mm in diameter; small basal lung condensations with mild pleural effusion, mild homogeneous splenomegaly, and a small amount of free fluid in the abdominal cavity at the bottom of the Douglas cul-de-sac. Possible respiratory and gynecological infections are treated with ampicillin/sulbactam together with doxycycline. The patient progresses with persistence of the symptoms. A lymph node biopsy is then performed, revealing a morphology compatible with Kikuchi-Fujimoto disease. Treatment with prednisone is initiated with a clinical and laboratory improvement in the patient's condition. Kikuchi-Fujimoto disease is probably under-reported and under-diagnosed due to the low index of suspicion. Greater awareness of this illness would result in clinicians arriving at this diagnosis more often.