Scoliosis is a curvature with a cobb angle exceeding 10 degrees in the coronal, axial and sagittal planes caused by the self-rotational motion of the spine. Lenke, developed a new adolescent idiopathic scoliosis system in 2001. The Lenke classification system is organized according to curve type with a sagittal thoracic modifier and a lumbar spine modifier. The sagittal profile has been included in a scoliosis classification system for the first time. In this review, Lenke classification and treatment planning were explained in detail and discussed with the literature. As a result, the Lenke classification system, with all its components, offers specific techniques to optimize coronal and sagittal curve corrections and balance in determining the spine regions to be fused.