Spinal dysraphism is usually accompanied with lumbosacral lipoma. The neurological deficits such as lower extremities sensorimotor disturbances, bowel and bladder dysfunction are produced by tethering, compression of lipoma and direct transmission of external force on the spinal cord during growth period. 25 patients treated surgically at our hospital between May, 1985, and January, 1993, were reviewed. Surgical approach was designed for debulking the lipomatous mass, untethering and decompressing the cord, repairing the dural defect and paraspinal muscle cleft. 2-59 months (mean 37.5 mons) after operation the 2 patients whose neurological system were normal before operation remained intact. In other 23 patients, bowel function recovered in 75%, active urination restored and improved in 66.2%. Motor dysfunction and paresthesia of the lower extremities alleviated in 78.3%. A case of mild uremia returned to normal and another moderate case improved. None was deteriorated by the operative procedure except one case in which a posterior nerve root was injured.