This trial assessed the consequences of discontinuation of nasal-CPAP in stable preterm infants breathing room air. Eighty-eight infants with a mean gestational age of 29 (24-33) weeks and a mean birthweight of 1264 (665-2060)g, randomized to either discontinuation of CPAP or its continuation, were clinically observed and monitored for 6 h by cardiorespiratory monitor, pulse oximeter and transcutaneous blood gas monitor. The abdominal circumference and gastric air and aspirate volumes were measured prior to meals at trial entry and after 6 h. Discontinuation of CPAP led to a small but significant decrease in oxygenation at 1 and 6 h. During the trial, five infants in the experimental group required supplemental oxygen and one infant was put back on CPAP owing to excessive apnoeas. Discontinuation of CPAP did not influence the TcPCO2 or the number of apnoeas and bradycardias during the trial, but led to significantly increased respiratory rate, retractions, and flaring at 6 h. It also led to a significant decrease in the abdominal circumference and gastric air volume. Thirty-nine percent of infants were put back on CPAP some time after the trial, mainly because of recurrent apnoeas and bradycardias. Taking the infant off CPAP during the trial reduced subsequent use of CPAP.