BACKGROUND: Poractant administration with thin catheter is gradually gaining popularity compared to the INSURE technique. However, there is little evidence to use thin catheters for administration of beractant. With this background, we compared the effect of beractant administration with INSURE vs thin catheter in preterm infants less than 34 weeks with RDS on death/chronic lung disease (CLD). METHODS: This prospective cohort study was conducted in a tertiary NICU where inborn preterm infants≤34 weeks with RDS receiving beractant by INSURE or thin catheter were studied over two epochs- Epoch1– INSURE (Jan 2020–Oct 2020) & Epoch 2– Surfactant through thin catheter (Nov 2020–July 2021).The primary outcome was occurrence of death/CLD. Procedure related complications like transient bradycardia/desaturation, pneumothorax, failure of procedure, rates of other outcomes like failure of CPAP within 72hr, duration of invasive mechanical ventilation/ CPAP support, oxygen supplementation, other major neonatal morbidities & mortality were evaluated as secondary outcomes. RESULTS: The combined outcome of death/CLD was significantly lower in the thin catheter epoch (RR 0.56, 95% CI 0.34-0.90, p = 0.012). When analyzed independently for death/CLD, we found significantly lower number of deaths in the thin catheter epoch (RR 0.44, 95% CI 0.23-0.83, p = 0.008). Number of infants who failed CPAP within 72 hrs of life was lower in thin catheter epoch (RR 0.59, 95% CI 0.41-0.85, p = 0.003). Transient bradycardia/desaturation was higher during thin catheter technique (RR 4.17, 95% CI 2.22-7.69, p < 0.001). Incidence of severe IVH was lower with thin catheter technique (RR 0.13, 95% CI 0.02-0.98, p = 0.034). CONCLUSION: Beractant administration by thin catheter reduces combined outcome of death/CLD.