The action of the gastrointestinal prokinetic drug cisapride was studied in 7 premature infants of whom 4 suffered from gastric stasis and GE reflux, and 3 had constipation. The postnatal age and weight at the start of treatment ranged from 30 to 36 wks and 815 to 1635 g. All infants received standard formula for premature infants (Nenatal, Nutricia). Cisapride was administered orally 4 × 0.2 mg/kg. day. The day before starting cisapride and after 7 days of treatment, gastro-emptying coefficient (GEC) was measured using the 13C-octanoic acid breath test and the changes in gestrointestinal motility was studied using the passage time of carmine red indices. In all children the GEC was improved after 7 days of treatment (n=7, range before treatment 1.69-3.34(mean 2.59) and after treatment 2.79 - 3.76 (mean 3.28)). The motility was slightly improved in only 2 patients (n=7, mean passage time before: 23.7 hrs compared with mean passage time after 7 days of treatment: 35.5 hrs). We therefore conclude that in premature infants cisapride treatment is only indicated to improve the gastric stasis and GE reflux but not to treat constidation.