Kikuchi-Fujimoto disease (KFD), also know as histiocytic necrotizing lymphadenitis, is a benign disorder characterized histologically by necrotic foci surrounded by histiocytic aggregates, and with the absence of neutrophils. KFD was recognized in Japan, where it was first described in 1972. The disease is most commonly affecting young women. The cause of the disease is unknown, and its exact pathogenesis has not yet been clarified. Many investigators have postulated viral etiology of KFD, connecting it with Epstein Barr virus, human herpes simplex virus 6 parvo B 19, but also with toxoplasmic infection. Kikuchi-Fujimoto disease is usually manifested with lymphadenopathy and high fever, and is associated with lymphopenia splenomegaly, and hepatomegaly with abnormal liver function tests arthralgia, and weight loss. The disease has the tendency of spontaneous remission, with mean duration of three months. Single recurrent episodes of KFD have been reported with many years’ pauses between the episodes. Kikuchi-Fujimoto disease may reflect systemic lupus erythematosus (SLE), and self-limited SLE-like conditions. Final diagnosis could only be established on the basis of typical morphological changes in the lymph node, and lymph node biopsy is needed for establishing the diagnosis. Lymphadenopathy in a patient with fever of the unknown origin could provide a clue to the diagnosis of lymphoma, tuberculosis, metastatic carcinoma, toxoplasmosis and infectious mononucleosis. As KFD does not have any classical clinical features and laboratory characteristics, it may lead to diagnostic confusion and erroneous treatment. We described a case of KFD, and suggested that this disease should be considered as a possible cause of fever of the unknown origin with lymphadenopathy.