The authors report on neurological damage caused by the use of sublaminar segmental fixation in the correction of vertebral deformities. Three groups were reviewed: 600 patients instrumented with Harrington rods and segmental wiring, 50 patients treated with the Hartshill system and 100 patients instrumented with Luque bars. All of the patients were operated on using sublaminar wiring fixation. We report two transitory neurological complications among the 600 patients with Harrington rod instrumentation and segmental wiring, two permanent neurological deficits among the 50 cases treated with the Hartshill system and none among the 100 patients instrumented using Luque bars. The purpose of this study is to analyse the causes of these neurological complications, which occurred late in all four of the cases described.