The authors have taken up previous studies by Martin (1969), and by Johnson (1973), and carried out an experimental study on white rats aimed at evaluating the morpho-functional changes of cells from the exocrine pancreas under the influence of 5-fluorouracil (Ftorafur), a cytostatic drug which is a general inhibitor of protein synthesis by cells. Ftorafur was injected in amounts of 2.3 mg/100 g of body weight, and a significant reduction was noted in the secretion of bicarbonates, amylase and lipase by the pancreas of the animals. Cytologic changes were also noted in the pancreatic tissue of these animals, indicating, on the one hand, a deficient protein and enzyme synthesis by the pancreatic cells, and a blocking of the mechanism of discharge of zymogen granules, on the other hand. The most intensive morpho-functional changes were noted following repeated administration of Ftorafur, probably due to the cumulative effects of this substance at the level of secretory pancreatic cells. The authors consider that 5-fluorouracil inhibits to a considerable degree the synthesis of pancreatic enzymes, and as such it can be used as a therapeutic means for the reduction of the external secretion of the pancreas.