Trial question: Does administration of exogenous surfactant using a minimally-invasive technique improve outcome in preterm infants 25-28 weeks gestation treated with continuous positive airway pressure (CPAP)? Trial hypothesis: That early surfactant administration via a minimally-invasive technique to preterm infants on CPAP will result in a lesser duration of mechanical respiratory support, and a higher incidence of survival without bronchopulmonary dysplasia. Trial design: Multicentre, randomised, masked, controlled trial in inborn preterm infants 25-28 weeks gestation, aged less than 6 hours, requiring CPAP because of respiratory distress, with an FiO2 of >=0.3 and CPAP pressure 5-8. Infants randomised to surfactant treatment receive 200 mg/kg of poractant alfa (Curosurf) administered under direct laryngoscopy using a surfactant instillation catheter, followed by reinstitution of CPAP. Controls continue on CPAP. The intervention is masked from the clinical team. Care thereafter is as per usual in both groups, other than the requirement to adhere to intubation criteria. The primary outcome is incidence of death or BPD. Secondary outcomes include incidence of death, major neonatal morbidities (BPD, intraventricular haemorrhage, periventricular leukomalacia, retinopathy of prematurity, necrotising enterocolitis), pneumothorax and patent ductus arteriosus; need for intubation and surfactant therapy; durations of mechanical respiratory support, intubation, CPAP, intubation and CPAP, high flow nasal cannula (HFNC), oxygen therapy, intensive care stay and hospitalisation; hospitalisation cost; applicability and safety of the MIST procedure; and outcome at 2 years. The sample size is 303/group, allowing detection of a 33% difference in the primary outcome with 90% power. The trial commenced at Royal Hobart Hospital December 2011 and Royal Women's Hospital during 2012, and will ultimately be conducted over 5 years in multiple centres internationally.