The purpose of this study is to evaluate whether the surgical correction of the scoliotic curve with the use of segmental pedicle screw fixation system is effective. We studied 20 patients (19 girls, 1 boy) with a mean age of 14,6 years (range from 13 to 22). The spinal deformities were evaluated by Cobb method with anteroposterior and lateral bending radiographs. There were 13 right thoracic curves and 7 left thoracolumbar curves. The width of the pedicles was estimated in all patients by computerized tomography of the thoracic and lumbar spine. Posterior instrumentation (Moss-Miami transpedicular system) was used and additional thoracoplasty was performed in 2 patients. The transpedicular screws were placed between T2 and L5. Intraoperatively the image intensification was indispensable and the wake-up test was always conducted. All the patients were assessed both clinically and radiographically at 3,6,9,12 months and annually until now. The average follow-up was two years. There was an average correction of 73% of the primary curve (pre-op standing average 59 degrees (range from 42 degrees to 87 degrees), lateral bending average 33 degrees (range from 10 degrees to 75 degrees), post-op average 13 degrees (range from 6 to 30 degrees), at last examination average 14 degrees (range from 6 degrees to 33 degrees). Infection and neurological complications were not noted. No major complications were observed. Exact evaluation of the pedicles by CT scan is an essential prerequisite for transpedicular screw insertion. The correction of idiopathic curves with the use of segmental pedicle screw fixation system is a very effective method(correction > 70%) It seems that control of the three columns of the spine by the transpedicular screws offers sufficient apical translation and coronal realignment.