The measurement of exhaled lung volumes following forced expiratory manoeuvres is widespread in paediatric and adult respiratory medicine but is not possible in the neonatal population as infants cannot execute commands or maximal efforts. Although forced manoeuvres can be mimicked in newborn infants by the application of an external force to simulate a forced exhalation, alternative lung function measures can also be used. These include tidal breathing analysis which can describe abnormal airway function, dynamic lung function monitoring with forced oscillometry or the utilisation of readily available modalities such as point-of-care lung ultrasonography. Non-invasive functional assessments which specifically target the pathophysiology of neonatal lung pathology such as the arrested alveolar growth can also be utilised.