When treating childhood acute lymphoblastic leukemia (ALL), secondary neoplasms are a significant long term problem. Radiation is generally accepted to be a major cause of the development of secondary neoplasms. Following treatment for ALL, a variety of secondary tumors, including brain tumors, hematologic malignancies, sarcomas, thyroid cancers, and skin cancers have been reported. However, oligodendroglioma as a secondary neoplasm is extremely rare. Herein we present a case of secondary oligodendroglioma occurring 13 years after the end of ALL treatment.