Achondroplasia is a congenital developmental condition characterized pathologically by defective enchondral ossification, affecting chiefly the long bones, and clinically by peculiar dwarfism with short extremities and normal trunk. One of the most common neurologic manifestation in achondroplastic patients in adulthood is spinal stenosis where the prominent characteristics of lumbar vertebrae structure are shortening of interpedicular distance and hypertrophy of vertebral pedicle. There has been no case report of traumatic cauda equina syndrome resulted in paraparesis among achondroplasic patients in Korea. We experienced a 30 year-old achondroplastic man sustained paraparesis as the result of an accidental slipping down. After the surgical decompression, the patient made slow recovery in all aspects of function via rehabilitation therapy.