This study set out to examine the effects of a Ca++ channel blocker, verapamil, on pancreatic exocrine secretion because of the known relationship between amylase secretion and intracellular Ca++. Pancreatic secretion was stimulated in dogs by infusing secretin and cholecystokinin. Verapamil was found to inhibit the secretion of amylase but to have no effect on lipase, trypsin, or total protein. There was no effect on the secretion of water and bicarbonate. To determine the possible physiologic significance of these findings, the pancreas was stimulated by a meat meal, and verapamil was found to inhibit amylase secretion again and in addition to inhibit the secretion of water and bicarbonate. The results suggest that verapamil has an inhibitory effect on amylase secretion by blocking the influx of Ca++ into the acinar cell and has an indirect effect leading to inhibition of water and bicarbonate secretion from the duct cells.