A 26-year-old man was hospitalized with a 1-month history of fever. Cervical lymph node biopsy showed necrosis in the paracortical area with abundant nuclear debris and proliferation of histiocytes. A diagnosis of histiocytic necrotizing lymphadenitis (HNL) (Kikuchi's disease) was made. He received methylprednisolone pulse therapy (MPT) (0.5 g/day for 3 days) without maintenance therapy and experienced dramatic improvement. We also used MPT for another 12 cases of HNL. All patients became afebrile within 1 day without adverse events. Four patients relapsed after the initial MPT, but only 1 patient relapsed during the following year. Our results suggest that MPT is warranted in HNL patients with prolonged fever.