A forty-eight-year-old woman with a 30 years history of tendinous xanthomatosis developed spastic gait and mild urinary incontinence. Myelography, metrizamide-enhanced CT and magnetic resonance image revealed multiple intradural-extramedullary tumors extending from C1 to Th7. The gait disturbance entirely disappeared by the removal of the tumors. Morphological examination of the tumors showed xanthogranulomatosis. The analysis of her sera and tumors revealed increased amount of plant sterols, especially beta-sitosterol and the diagnosis was made as beta-sitosterolemia. Tendinous xanthoma and beta-sitosterolemia were seen in 2 of 6 her brothers but none showed neurological symptoms. This is the first case of sitosterolemia with neurological complication i.e., spinal cord compression due to extramedullary sitosterolemia xanthomas.