Kikuchi-Fujimoto disease or histiocytic necrotizing lymphadenitis is a rare, benign condition, usually self-limited to a six-month period. Classic clinical presentation is characterized by cervical lymphadenopathy, leukopenia and prolonged fever. It affects principally young, Asiatic adult women, although a few cases in the pediatric population have been reported. This disease frequently mimics tuberculous lymphadenitis, malign lymphoma, systemic lupus erythematosus and other benign and malignant conditions. The etiology is unknown, although a viral or autoimmune pathogenesis has been suggested. Laboratory investigations are usually unremarkable, and the most frequent findings are leukopenia, elevated erythrocyte sedimentation rate, anemia and positive antinuclear antibodies. To make an accurate diagnosis, histopathological studies are required. To avoid the use of antibiotics (which have no effect), early diagnosis is necessary. Herein the case of a 10 years old girl is described that presented with high, prolonged fever and marked cervical lymphadenopathy secondary to Kikuchi-Fujimoto disease.