Seventeen children with spinal cord injuries that occurred before the age of 9 years were followed at the Alfred I. duPont Institute for a mean of 13.2 years (range 3-32 years). Fourteen of these patients (82%) developed subluxation or dislocation in one or both hips. Patients with spastic spinal cord injury (SCI) developed hip flexion and adduction contractures and had symptoms that tended to mimic those of cerebral palsy. Patients with flaccid SCI mirrored the "flail" hips of myelomeningocele. Pelvic obliquity occurred in spastic and flaccid children. Only one patient developed pain, and three had deformities suggesting avascular necrosis of the femoral head. At final follow-up, no patient had physical problems relating to the hip dysplasia.