In this study, a 2.5-year-old boy suffering from a febrile seizure with normal laboratory tests and a history of immune hemolytic anemia was examined. Brain MRI demonstrated some tumors in the frontal, parietal, and occipital lobe that corroborated the pathology results of primary central nervous system lymphoma for the patient. The patient was treated with high-dose of Methotrexate. Our result suggested regular and careful monitoring of patients with autoimmune hemolytic anemia in order to control the manifestations of concomitant disease such as lymphoma that may develop later.