The authors report a case of hereditary multiple exostoses (HME) with neurologic complications, and review the literature. A 23-year-old man exhibited a worsening spastic paraparesis with sphincter dysfunction. The cranial nerves and the exteroceptive and deep sensations were apparently undamaged. The family history, the physical examination, and the systemic radiologic examination revealed all the characteristics of HME. The neurologic complication was caused by an exostosis, arising from the C2 right hemilamina, compressing the spinal cord. The patient quickly improved after a laminectomy.