Gangliogliomas of the spinal cord are very unusual and the anaplastic variant of these tumors is extremely rare. In spinal anaplastic gangliogliomas, malignant changes (hypercellularity, vascular proliferation, necrosis, high numbers of mitotic figures) are typically evident in the glial element of the tumor. Gangliogliomas can arise in any part of the central nervous system and the features of adult and pediatric cases differ significantly. We describe the case of a pediatric patient who had a spinal anaplastic ganglioglioma extending from the T-9 to the L-3 level. The signs at presentation were bilateral knee flexion (quadriceps weakness) while walking and intermittent urinary incontinence. The tumor was partially resected with an ultrasonic aspirator, but the patient's neurological status deteriorated as a result and adjuvant radiotherapy did not resolve the deficit. Copyright (c) 2006 S. Karger AG, Basel.