Intramedullary spinal cord high-grade gliomas are rare and almost always fatal pediatric tumors. The current treatment paradigms are surgery, and radiotherapy. This is the first description of a toddler with an intramedullary cervical high-grade glioma harboring an anaplastic lymphoma kinase (ALK) fusion (KIF5B) whose treatment with the ALK inhibitor, alectinib, achieved clinical and radiological evidence of complete remission after six months of treatment. Our findings suggest that ALK inhibitors may emerge as an effective therapy in malignant spinal tumors with a dismal prognosis.