A benign intradural teratoma of the lumbar spine was studied with myelography, CT, magnetic resonance imaging, and histologic correlation. The tumor was composed of three portions (adipose tissue, neurofibrous tissue containing a large duct, and a keratinous cyst). Computed tomography distinguished the fat and the solid tissue from surrounding CSF but failed to differentiate the keratinous component of the mass. Magnetic resonance adequately demonstrated all three main components of the tumor.