The haemodynamic effects of intravenous injection into the test animals themselves of peritoneal exudate obtained during experimental acute pancreatitis in pigs were studied. The exudate had a distinct but moderate vasodilating effect when injected into the test animal. This decrease in afterload and a slight compensatory increase in heart rate led to a small increase in cardiac output. The profound hypotensive effect of intravenous injection of peritoneal pancreatic exudate observed by others when injecting the exudate into healthy animals could not be reproduced. In an organism severely affected by pancreatitis, the added pharmacological insult of peritoneal exudate intravenously seems to be of little haemodynamic consequence. Some of the effects previously reported may be caused by trypsin added to the fluid injected intraductally to produce the ailment.