Gangliogliomas (GGs) are a small subset of intramedullary spinal cord tumors in children. The anaplastic variant (WHO grade III) appears to be an extreme rarity. A literature research revealed only 15 case reports of intramedullary anaplastic GGs (aGGs) and only 4 pediatric patients. The course of an 18-month-old boy with sudden onset of paraparesis is presented. Spinal MRI revealed a contrast-enhancing intramedullary tumor ranging from T6 to T12. The patient underwent a standard laminectomy/laminoplasty and gross total resection of the lesion. His neurological status remained unchanged postoperatively and he recovered very well during outpatient neurorehabilitation. Neuropathologic examination revealed an aGG of WHO grade III. Because of the high-grade histology, adjuvant radiotherapy and chemotherapy with temozolomide were administered. The patient subsequently recovered to a normal functional status. Clinical and radiographic progression-free survival is now 4 years. Based on an extensive literature review, this is only the fifth pediatric patient with a primary intramedullary aGG and the second with documented progression-free survival of over 4 years. Another 4 primary intramedullary aGGs in adults and 7 patients with spinal dissemination from a cerebral aGG or malignant transformation of a low-grade GG have been reported. In comparison to the published case reports, which often indicate significant neurological dysfunction and rather short survival, the neurological recovery in this patient was favorable, and the oncologic outcome even more so. This is an argument for the use of the aggressive treatment regimen of complete resection followed by radio- and chemotherapy applied here.