BACKGROUND Meconium stained amniotic fluid (MSAF) occurs in around 14 % of all pregnancies, but only a minority of these children will develop meconium aspiration syndrome (MAS). In the Netherlands, infants born through MSAF, are often admitted for a 24-hour observation period. We questioned the usefulness of postnatal hospital observation in vigorously born infants. OBJECTIVE the aim of this study was to evaluate the usefulness of a 24-hour hospital observation period of newborn infants born through MSAF. DESIGN/METHOD Newborn infants, born through MSAF, from two local hospitals (total 3200 deliveries) were included for whom a pediatrician was consulted. Infants were divided based on Apgar score, i.e. a 5-minute Apgar score of 9 or 10 (vigorous infants) (group 1) or below 9 (group 2). Gestational age, maternal fever, antenatal fetal monitoring (CTG), duration of rupture of membranes, mode of delivery, arterial umbilical pH, 1 and 5-minute Apgar scores, and postnatal course were recorded. Chest X-rays were not routinely performed. RESULTS 171 patients were enrolled: 113 in group 1 and 58 in group 2. None of the group 1 infants developed MAS or had a chest X-ray performed. Four patients from group 2 developed MAS (5-minute Apgar scores respectively 6,7,7 and 8). These infants, all first born and full term, had an arterial umbilical pH<7,20. In 3 mothers CTG abnormalities were observed; 1 mother had fever. From the 54 infants (group 2) without MAS, 1 child died of asphyxia. CONCLUSION This study shows that a 24-hour hospital observation period of newborn infants born through MSAF with a 5-minute Apgar score of 9 or 10 has no added value. Even in the group with 5-minute Apgar scores below 9 only 4 (6,9%) children developed MAS. Using the 5-minute Apgar score vigorous infants can safely be discharged.