BACKGROUND: The aim of the study was the description and review of a diagnostic management for treatment of patent ductus arteriosus in preterm neonates. Indomethacin, widely used to effect nonoperative closure of patent ductus arteriosus, has been implicated in vasoactive side effects and requires an accurate diagnosis. PATIENTS AND METHODS: Firstly, the hemodynamic significance of the ductus arteriosus was assessed by clinical signs, such as tachycardia, disturbed microcirculation and a high difference of central and peripheral temperature. The patent ductus arteriosus was confirmed by echocardiography. The left ventricular systolic time intervals and the cerebral perfusion were obtained by pulsed doppler recordings. 48 preterm infants below 1500 g were investigated within the first 12 hours of life and during the first week. RESULTS: In 32 preterm neonates (67 %) a patent ductus arteriosus without hemodynamic significance and in 9 neonates a patent ductus arteriosus with hemodynamic changes was detected. In 9 neonates there were no signs of patent ductus arteriosus. Neonates with typical clinical signs of patent ductus arteriosus exhibited significantly diminished preejection time, prolonged ejection time and a decreased quotient of preejection and ejection time. We found pathologically changed parameters of anterior cerebral artery in neonates with clinical signs of patent ductus arteriosus. To judge the efficiency of the diagnostic management the groups of neonates were compared concerning the evidence of complications. Neonates with ductus arteriosus but without therapy did not reveal more pulmonary problems as well as intracerebral hemorrhages, renal or intestinal disturbances than the group of neonates with treated ductus arteriosus. CONCLUSIONS: Summarizing, we suggest that the described criteria are to be taken into account before treatment of ductus arteriosus in preterm neonates. In this way a wide clinical and echocardiographical investigation will be performed in risk neonates and a useless therapy can be avoided.