Abstract Background: Lateral column lengthening is currently the most attractive procedure to correct the deformity. In this study we aimed to evaluate the effect of lateral column lengthening as a single or combined procedure on the clinical and radiological outcome of symptomatic patients with flexible flatfoot. Aim of Study: This study aims was to evaluate the effect of lateral column lengthening as a single or combined proce-dure on the clinical and radiological outcome of symptomatic patients with flexible flatfoot. Prospective study. Patients and Methods: 24 pediatric patients with sympto-matic flexible flatfoot. Post-operative evaluation was done via AOFAS Ankle-hindfoot Scale. Results: There were significant improvements of the radiological alignment angles post-operatively. Also asignif-icant improvement of AOFAS score after 3 months post-operatively and the end of follow-up is noticed. Concerning complications, persistent pain (8.4%), delayed union (8.4%), graft site hematoma (4.2%), partial graft extrusion (4.2%) and wound dehiscence (4.2%). Conclusion: Lateral column lengthening in treatment of pediatric flexible flatfoot has a good clinical and radiological outcome. It is associated with few or minor post-operative complications.