Between 1982 and 1987 27 Nissen's fundoplications were carried out in our institution. Postoperatively 7 infants showed a typical dumping syndrome. The symptoms were irritability, pallor, sweating, tachycardia, lethargy, diarrhoea and vomiting. In all cases an absolute refusal of feeding was observed. The diagnosis was confirmed by a typical early postprandial hyperglycaemia with hyperinsulinaemia leading to a reactive hypoglycaemia. Additionally, we were able to demonstrate an increased HbA1c as an expression of recurrent hyperglycaemias in 3 infants. In 6 infants the dumping syndrome was of short duration and the symptoms disappeared after application of a so-called dumping diet. In this diet the easily resorbable carbohydrates are replaced by uncooked starch. But in one case we were forced to use continuous enteral nutrition because of persistence of the symptoms 1 year after the Nissen fundoplication. Complete refusal of feeding is an early symptom of the dumping syndrome. If this symptom is observed after a Nissen's fundoplication, a dumping syndrome must be excluded.