Adolescent idiopathic scoliosis (AIS) is a complex 3D deformity of the spine. Its prevalence is 2% in the general population , with almost 10% requiring surgery.Spinal instrumentation in AIS aims to correct the deformity and maintain long term stability of the spine till the bone healing is ensured , the purpose of this study is to compare between the preoperative and post operative radiographic and results of posterior spinal fusion in AIS using the whole pedicle screw technique and the hybrid technique ( hooks= pedicle screws) . Objective: This thesis aims to provide analytical comparison between whole pedicle screws , and the hybrid instrumentation (hooks + pedicle screws ) in posterior spinal fusion in AIS . Methods: This study is conducted on 28 patients fulfilling the inclusion criteria( between 12-20 years old ) with AIS admitted at the spine unit in KASR AL AINI hospital .Patients were divided in 2 groups on simple randomized basis , one group will be operated using the whole pedicle screws while the other group will be operated using the hybrid technique (hooks + pedicle screws) for posterior spinal fusion and correction of deformity using neurophysiological monitoring in patients as needed . Results: our study included 28 patients ,seven males(25%), twenty one females (75%),the mean age in our study was 15.5±2.5 , twenty one patients were operated using the pedicle technique , while seven patients were operated using the hybrid technique ,the mean of operative time was 3.5±0.9 , the mean of blood loss was 607.1±244 , seventeen patients (60.7%) had levelled shoulders , ten patients (35.7%) had right shoulder up , one patient had left shoulder up ,the mean of cobb angle in our cases was 59.4±15.2 , while the mean of cobb angle post 11.8±7.9 ,in our study there were (85.7 %) improvement rate more than 70% concerning the cobb angle , (75%) improvement rate more than 70% in apical vertebral translation in all cases , Conclusion: As per our results , the earlier the correction for AIS , the better radiographic curve correction ,the earlier the surgery the better height improvement due to increased flexibility , pedicle screws and hybrid system provides great correction of spinal deformities.