The aim of this study was to determine the long-term outcome of neurosurgical untethering on neurosegmental motor level and ambulation level in children with tethered spinal cord syndrome. Forty-four children were operated on (17 males, 27 females; mean age at operation 6 years 2 months, SD 5 years). Sixteen patients had myelomeningocele, nine had lipomyelomeningocele, and 19 had other types of spinal dysraphism. Motor level and ambulation level were assessed pre- and three times postsurgery (mean duration of follow-up 7 years 1 month, SD 1 year 8 months). Deterioration of motor level was seen in five of 44 patients, 36 of 44 remained stable, while improvement was seen in three of 44 patients. Deterioration of ambulation level was seen in five of 44 patients, and remained stable in 26 of 44. Thirteen of 44 children were too young to ambulate at time of operation (<2 years 6 months). Late deterioration of motor or ambulation level was only seen in (lipo)myelomeningocele patients. Deterioration of ambulatory status was strongly associated with obesity and retethering. Revision of the initial tethered cord release was performed in nine of 44 patients, mainly in those with lipomyelomeningocele.