This lecture written and narrated by Dr Mario Di Silvestre, talks about the pre-op assessment and preparation in major spinal corrective surgery in the paediatric population. The lecture begins with a discussion of the assessment of cardiopulmonary functions in relation to the paediatric population and their compromise due to deformity, followed by a consideration of the disorders affecting the children such as hematological, nutritional and metabolic which require special attention and optimisation before corrective surgery. The neuromuscular disorders are discussed from an anesthesia point of view and the necessary precautions to be taken are described. Finally, the clinical examination and radiological examination, which are mandatory for surgical planning, are described.