['To measure the effect of nasal continuous positive airway pressure (CPAP) on intestinal blood flow velocity responses to enteral feedings and left ventricular output (LVO).', "Eighteen infants completed the study (birth weight 1793+/-350 g, gestational age 32.1+/-1.1 weeks). On the day infants were weaned from CPAP to room air, pre- and postprandial (0, 30, 60 and 90 min after feeding) mean velocity (MV), peak systolic velocity (PSV) and end diastolic velocity (EDV) were measured for one feeding given when receiving CPAP ('on CPAP'), and for one feeding given after CPAP had been discontinued ('off CPAP'). Preprandial LVO was measured before and after CPAP discontinuation.", 'MV and PSV were significantly lower when infants were on CPAP (P<0.05). Maximum postprandial MV, PSV and EDV occurred at 30 min when on CPAP and at 60 min when off CPAP. Preprandial LVO was similar when infants were on and off CPAP.'] Does nasal continuous positive airway pressure affect pre- and postprandial intestinal blood flow velocity in preterm infants?