Early Onset Scoliosis (EOS) may be associated with long-term pulmonary morbidity, which is not commonly seen in Adolescent Idiopathic Scoliosis. Initial evaluation is based on determining any underlying etiology related to congenital or syndromic conditions. Assessing the impact of scoliosis on thoracic development may help guide treatment, which is often required at a young age in these children to prevent irreversible pulmonary insufficiency. Treatment is based on multiple factors but may include non-surgical strategies, such as casting or bracing, along with growth-sparing surgical procedures using growing rods or chest wall expansion. Definitive fusion is rarely indicated in young patients. This chapter will cover the diagnosis, evaluation, and treatment of children with EOS.