The effect of raw black gram and black gram trypsin inhibitory fraction on the pancreatic function of male albino mice has been evaluated. Animals were fed autoclaved black gram (Group I), raw black gram (Group II) and autoclaved black gram incorporated with black gram trypsin inhibitory fraction (Group III). Pancreatic total protease, trypsin and amylase activities were elevated significantly in Group II and III animals. Analyses of intestinal contents showed a constant level of total protease activity in all the groups, along with a significant reduction in trypsin level in Groups II and III. Increased U-14C-lysine incorporation in pancreas and an enhanced level of amylase in intestinal contents show the hyperactivity of the pancreas in Groups II and III. Pancreas weights increased in Groups II and III. Pancreatic protein/mg pancreas and RNA/DNA ratio remained constant in all three groups. It is concluded with histological studies that the black gram trypsin inhibitor increased the pancreatic activity of mice by developing the cellular hyperplasia of the pancreas.