The pharmacokinetics of a contrast medium in experimental pancreatography of 17 piglets were studied by repeated radiographs of the pancreas and by measuring the concentration of I125-labelled CM in the portal vein, inferior vena cava and in the thoracic duct. Intraduodenal and portal vein injections were performed for comparison. Contrast enhancement of the pancreas after pancreatography was measured by CT. High concentrations of CM were seen in the portal vein 40 seconds after pancreatography, demonstrating direct absorption into the local veins. The concentration of CM in lymph exceeded the systemic concentration 15 minutes after injection, suggesting absorption into lymphatic vessels from the pancreas. CT revealed parenchymal filling of the pancreas even though no acinar filling was seen in normal radiographs. This suggests "invisible" parenchymal filling during normal pancreatography.