This is a descriptive video of preschool and paediatric lung function testing. It has been created by the team in the Division of Paediatric Pulmonology, Department of Paediatrics, University of Cape Town. This video is intended to be educational for children and families undertaking these measures; and for health care workers training in the optimal collection of these measures. This video was filmed and distributed with the consent of all involved, during June and October 2023, and follow current consensus recommendations for lung function testing in children.