Apelin and its APJ receptor are present inter alia in colostrum and in the young animal gastrointestinal tract. This peptide exerts numerous effects participating in the appetite and drinking behaviour, gastric acid and insulin secretion. The aim of the study was to investigate the effect of apelin-13 on the activity of pancreatic and gastric enzymes in young animals. The two experiments were carried out on weaning Wistar rats (50 ± 10 g) which received the apelin-13 or physiological saline (in the corresponding control groups) by intragastric or intraperitoneal way twice a day for 10 days (100 nmol · kg^–1 body weight). At the end of each experiment rats were sacrificed and blood samples were collected for apelin and cholecystokinin (CCK) radioimmunoassay. The fragments of the pancreas and stomach were weighted and frozen for the further digestive enzymes activity analysis. The intragastric and intraperitoneal administration of apelin-13 increased plasma CCK level in young rats. The intraperitoneal injection of apelin-13 stimulated pancreatic trypsin, α-amylase and lipase activity, but had no effect on the activity of gastric enzymes. On the other hand, the intragastric administration of apelin-13 stimulated only the activity of pancreatic lipase and had no effect on the activity of gastric pepsin and rennet. So, circulating apelin exerts the most pronounced effect on pancreatic enzymes activity in young rats, but neither circulating nor luminal apelin influences gastric enzymes activity. Regardless the route of administration, apelin stimulates lipase activity which points out its considerable role in the regulation of the fat digestion.