Pulsed doppler recordings were obtained in the truncus coeliacus in 12 premature born infants (gestational age 30.3 +/- 2.5 weeks) with the clinical signs of patent ductus arteriosus Botalli (PDA) and compared to a control group of 24 healthy infants (gestational age 40.5 +/- 5.3 weeks). In all children the maximal systolic velocity, the endsystolic and the enddiastolic velocity and the pulsatility-index were measured. The 24 healthy newborns showed the following velocities: Maximal systolic velocity: 77 +/- 16 cm X s-1; endsystolic velocity: 31 +/- 10 cm X s-1; enddiastolic velocity; 18 +/- 9 cm X s-1. The pulsatility-index was 0.75 +/- 0.11. In children with PDA the maximal systolic velocity was 72 +/- 21 cm X s-1, the endsystolic velocity 15 +/- 14 cm X s-1 and the enddiastolic velocity -5 +/- 8 cm X s-1. The pulsatility-index was 1.08 +/- 0.12. All infants with large PDA showed a significant decrease of the endsystolic velocity and enddiastolic velocity, whereas the pulsatility-index was significantly increased. The decrease of the endsystolic and enddiastolic velocity in infants with large PDA in comparison to the healthy control group may lead to hypoxemic-ischemic lesions of the intestinal organs. The increased incidence of necrotizing enterocolitis in premature infants with large PDA may be the result of hypoperfusion of the small bowel.