Two groups of patients with complex scoliosis problems are presented. The majority of patients had neurogenic scoliosis. Thirty patients (Group A) had Harrington instrumentation with segmental wiring and were immobilized postoperatively. Instrument stability was best when sacral fixation was not required. Pseudarthrosis was especially likely when there was deficiency of posterior elements. Ten patients (Group B) had double L rod instrumentation, and six had no postoperative immobilization. Correction was maintained except in two patients with kyphotic curves. There were transient neurologic complications in both groups, nerve root contusion being the most common (four cases). It is concluded that segmental instrumentation provides significant improvement in stability over conventional Harrington instrumentation. The advantages of added stability must be weighed against the increased potential for neurologic complications.