Scoliosis is a permanent lateral deflection of backbone, associated to a vertebra's rotation and twisting on their vertical axle, and it is one of more common diseases of pediatric age. It exist a great difference between the structural conformations, that are true pathologies, and the functional ones or paramorphisms, without bony alterations. Since about 80% of real scoliosis is idiopathic. The pediatrician's task is of precociously identify the appearance of a scoliotic bend and differentiate the structural and evolutive shapes from simple scoliotic posture. Therefore for ten years, in the preventive medicine programme of school age, we affected a scoliosis research in the secondary school using as clinical method the "bending test" that appraises three essential parameters: size's triangle, gibbus and limbs' asymmetry. Before examination an anamnestic form is compiled and the sexual maturity's degree is appraised. The subjects with suspect of scoliosis are asked to a subsequential control performed in our department's ambulatory service by a doctor of Scoliosis's Center of Pozzolatico (Florence), in order to decide whether to take radiographs and to define, if necessary, treatment. We verified 4453 pupils and of these the 8.9% has been asked to the specialist's control. Of these 106, namely the 2.8% of total pattern, have been X-rayed and 46, namely the 0.9% of total pattern, have been orthopaedically treated because affected by evolutive scoliosis. If we consider the last quinquennium's statistics, we remark that treatment's incidence is lower to 0.4% conforming to literature's data. We never observed false negatives whereas false positive have been only 0.8% of total pattern.(ABSTRACT TRUNCATED AT 250 WORDS)