Objective:To determine the effectiveness of posterior Moss-Miami transpedicular system for the treatment of adolescent idiopathic scoliosis in 24 patients with a 2-year minimum follow up. Methods:24 patients who underwent operations between September 2002 and November 2003 were evaluated for curve correction, spinal balance, and complications. Age at surgery averaged 13.8 years (range from 10 to20). The spinal deformities were evaluated by Cobb method with anteroposterior and lateral bending radiographs. All patients were right thoracic curves. Posterior instrumentation (Moss-Miami transpedicular system) was used. The transpedicular screws were placed between T2 and L2. All the patients were assessed both clinically and radiographically. Follow-up averaged 2.8 years. Results: There was an average correction of 72% of the primary curve (pre-operation standing average 54 degrees (range from 40 to 67degrees), post-operation average 15.2 degrees (range from 2 to 27 degrees), at last examination average 16.1 degrees (range from 2 to 30 degrees). Infection and neurological complications were not noted. No major complications were observed. Conclusions: Frontal and sagittal thoracic curve correction of thoracic scoliosis can be satisfactorily obtained using Moss Miami transpedicular instrumentation. It seems that control of the three columns of the spine by the transpedicular screws offers sufficient apical translation and coronal realignment.