The effect of lactic acid supplementation to the starter diet, on pancreatic secretion in pigs after weaning was studied in three crossbred piglets (Duroc, Danish Landrace and Yorkshire). The pigs were weaned at 28 days of age, and adapted to live in metabolic cages for one week, after which the piglets were surgically fitted with a pancreatic duct catheter and a duodenal T-cannula for chronic collection of the pancreatic juice. Studies were then carried out over a period of three weeks, during which the piglets were fed three times a day (at 08.00, 15.00, and 22.00 h). During period I, the piglets were fed with a standard weaner diet (control), during period II with a standard weaner diet supplemented with 2.5 % lactic acid period (lactic acid) and during period III with a standard weaner diet (control). Beginning four days after surgery, samples of pancreatic juice were taken hourly from 08.00 to 16.00 h. During period II, when lactic acid was added to the feed, the mean for all measured parameters of pancreatic secretion, except bicarbonate, increased in comparison to their values during period I. However this increase was only significant for volume and protein content. In contrast, during period III, when lactic acid was removed, there were no statistically significant changes in any of the measured parameters of pancreatic secretion compared to their values in period II. Our data strongly indicate that dietary supplementation with lactic acid stimulates pancreatic secretion in piglets after weaning.