Objective: To determine whether postextubation respiratory support via heated, humidified, high-flow nasal cannulae (HHHFNC) results in a greater proportion of infants younger than 32 weeks' gestation being successfully extubated after a period of endotracheal positive pressure ventilation compared with conventional nasal continuous positive airway pressure (NCPAP). Study design: We randomly assigned preterm ventilated infants to Vapotherm HHHFNC or NCPAP after extubation. The primary outcome, extubation failure, was defined by prespecified failure criteria in the 7 days after extubation. Results: A total of 132 ventilated infants younger than 32 weeks' gestation were randomized to receive either HHHFNC (n = 67) or NCPAP (n = 65). Extubation failure occurred in 15 (22%) of the HHHFNC group compared with 22 (34%) of the NCPAP group. There was no difference in the number of infants reintubated in the first week. Treatment with HHHFNC reduced the nasal trauma score 3.1 (SD 7.2) versus NCPAP 11.8 (SD 10.7), P < .001. Conclusions: HHHFNC and NCPAP produced similar rates of extubation failure.