Management of atelectasis and lung collapse in ventilated neonates remains a common challenge in the neonatal intensive care unit. Recombinant human DNase (rhDNase) is an established treatment of atelectasis in cystic fibrosis and its use is also reported in the management of asthma, respiratory syncitial virus bronchiolitis and bronchiectasis to liquefy sputum and aid its clearance from the lungs. We report the use of rhDNase in a subgroup of ventilated neonates with severe end-stage respiratory failure and atelectasis. Three of the four patients showed clinical improvement. A previously undiagnosed lung anomaly was subsequently identified in the fourth patient. Future randomized studies could examine any potential benefits of this emerging therapy.