The results of this study demonstrate that there are large differences in the amount of pancreatic juice secreted and in the chemical and enzymatic composition of pancreatic juice when the pouch and the catheter methods were used, and these differences must be taken into consideration in future studies with either method. A study was performed to compare the two most commonly used methods to collect pancreatic juice from growing pigs; namely, the pouch method (PM) and the catheter method (CM). In the first part of the study, three barrows (initial weight 37 kg) were fitted with a pancreatic pouch re-entrant cannula. An isolated pouch was prepared in which the pancreatic duct enters the duodenum. In the second part of the study, also with three barrows (initial weight 32 kg), a catheter was inserted into the pancreatic duct. At several points during the 24-h collection, the hourly rate of pancreatic juice secretion in CM pigs was larger (p < 0.05) than for PM pigs. CM pigs also had a higher (p < 0.05) daily volume of secretion, 4.09 vs 2.63 L/24 h for PM pigs. The pH of pancreatic juice collected from CM pigs was consistently higher (p < 0.01) throughout the 24-h collection. In contrast, the concentration and daily output of bicarbonate did not differ between CM and PM pigs. The concentration of protein in pancreatic juice from PM pigs (7.21 g/L) was higher (p < 0.001) than for CM pigs (4.08 g/L). Specific amylase and lipase and total amylase activities were greater (p < 0.01) in pancreatic juice collected from PM pigs. Specific and total carboxyl ester hydrolase and colipase activities were substantially (p < 0.01) larger in pancreatic juice collected from CM pigs. A major difference between the methods was that trypsin and chymotrypsin were fully active in pancreatic juice from PM pigs, whereas virtually no trypsin or chymotrypsin activity was detected in pancreatic juice from CM pigs. Specific and total chymotrypsin activities did not differ between PM and CM pigs. Both specific and total trypsin activities were substantially higher in pancreatic juice from CM pigs: 3682 U/L and 12,752 U/24 h, respectively, vs 1031 U/L and 2639 U/24 h, respectively, in pancreatic juice from PM pigs.