Compared to their intracranial counterparts, spinal cord tumors are quite rare, accounting for less than 10% of all central nervous system (CNS) lesions. Intramedullary spinal cord tumors (IMSCTs) comprise 20–30% of all spinal cord tumors in adults and 4–10% of all tumors of the spinal cord in children. The most frequently encountered IMSCTs are gliomas. In adults, the most common pathology is ependymoma followed by astrocytoma, comprising 60% and 30% of intramedullary spinal cord tumors, respectively. Children demonstrate the opposite incidence of pathology with astrocytomas being the most common (60%) followed by ependymoma (30%), while embryonal tumors, such as primary neuroectodermal tumors as described by the prior World Health Organization (WHO) classification, represent 4%. There has also been observed a pattern based on the age of the child. Children younger than 2 years of age will more commonly have neuroblastomas, teratomas, or dermoid tumors. Children ages 2–5 years present with astrocytomas, gangliogliomas, and epidermoid tumors. Children 6–10 year of age have a mix of tumor types. Astrocytomas predominate in children >10 years of age. Astrocytomas comprise approximately 90% of all intramedullary tumors in patients >10 years of age and about 60% of adolescent intramedullary neoplasms. By around 30 years of age, ependymomas become slightly more common than astrocytomas and predominate in the middle decades of life. After the sixth decade of life, astrocytomas and ependymomas are encountered with fairly equal frequency. Other IMSCTs include gangliogliomas, lipomas, subependymomas, hemangioblastomas, dermoids, teratomas, central neurocytomas, oligodendrogliomas, and in extremely rare cases, intramedullary metastases. There is a slight predilection for such lesions in males. A propensity for the development of spinal cord astrocytomas exists in children with neurofibromatosis type 1 (NF1). There is an additional propensity for the development of spinal cord ependymomas in children with neurofibromatosis 2 (NF2). In this chapter we are focusing on the most common malignant spinal cord tumors, astrocytomas and ependymomas, their differential diagnosis, diagnostic features, management and disease course.