The authors describe two children with Kikuchi necrotizing lymphadenitis, the main manifestations of which were cervical lymphadenopathy, fatigue, and fever. The diagnosis was based on histopathologic findings after open biopsy. Results of serologic studies, immunoperoxidase staining for Epstein-Barr virus (EBV) latent membrane protein, in situ hybridization for Epstein-Barr encoded RNAs, and polymerase chain reaction amplification of EBV Epstein-Barr nuclear antigen-1 (EBNA) DNA suggested that EBV was the causative agent in both patients. The disease was mild and subsided after complete surgical resection in one patient, with a follow-up of 1 year. In the other patient, a short course of corticosteroids led to complete clinical remission within 2 months, but the child still has biologic signs of persistent EBV infection. He experienced relapse with a large cervical mass and fever 28 months after the initial onset. Histologic findings were identical to those at initial presentation. Symptoms again resolved spontaneously within 2 weeks, but the follow-up was short (12 mos) and the child's EBNA antibodies are still absent. No evidence of immunodeficiency was found in either child. The cause of Kikuchi disease is unknown, but a viral or postviral hyperimmune reaction has been proposed. Malignant lymphoma and systemic lupus erythematosus are differential diagnoses. Early recognition of Kikuchi disease minimizes potentially harmful and unnecessary investigations and treatments. These findings add Kikuchi disease to the protean manifestations of chronic EBV infection.