Systemic or inhaled steroids are regularly prescribed to the preterm infant, since the incidence of bronchopulmonary dysplasia remains high. Their short-term beneficial effects should be weighed against their potentially very severe long-term deleterious effects. Their impact on lung growth and development is time-, dose- and steroid dependent, although this has been less well studied compared to the brain. Dexamethasone has been shown to be the most high-risk molecule, but given that the other steroid agents have not been proved entirely innocuous, further randomized studies are urgently required.