OBJECTIVE: To compare different radiographic methods of spine evaluation to estimate the reducibility and flexibility of the scoliosis curves. METHODS: Twenty one patients with Lenke types I and III adolescent idiopathic scoliosis (AIS) were included. Radiographic evaluations were made preoperatively on the orthostatic, supine decubitus with lateral inclination to the right and left and supine positions with manual reduction, with support in the apex of each curve on the X-ray table. On the day of surgery, when the patient was anesthetized, radiography was taken with longitudinal traction through divergent forces, holding under the arms and ankles, and with translational force at the apex of the deformity for curve correction. After one week, a post-operative radiography was performed in orthostatic position. RESULTS: The correction and flexibility of the main thoracic and thoracic/lumbar curves were statistically different between the supine radiographs, manual reduction, modified traction under general anesthesia, lateral inclination and postoperatively. The modified maneuver for traction under general anesthesia is the one which showed greater flexibility, besides presenting higher radiographic similarity to postoperative aspects. CONCLUSION: Among the radiographic modalities evaluated the study under anesthesia with traction and reduction showed better correlation with postoperative radiographic appearance. Level of Evidence IV, Case Series.