Two experiments, each on 6 sheep of about 40 kg liveweight, fitted with a catheter in the common bile duct and a T-piece cannula in the duodenum, were conducted to assess the influence of fibre (Experiment 1) and protein (Experiment 2) in the diet on exocrine pancreatic and bile secretion. Three isonitrogenous diets made of meadow hay and concentrate containing 134 (LF), 200 (MF) or 313 (HF) g/kg crude fibre (Experiment 1) and three diets containing similar levels of fibre and 130 (LP), 170 (MP) and 200 (HP) g/kg crude protein (Experiment 2) were fed. Mean volumes of bile-pancreatic juice and total nitrogen content were not affected by the level of fibre and amounted to 1294 ml and 3.11 g/24 h, respectively. Mean volumes of secretions were higher (P<0.01) on the HP than on the LP and MP diets. Total nitrogen was higher (P<0.05) on HP (3.35 g/24 h) than on LP and MP (2.66 g/24 h). Total activity (U/24 h) of trypsin and chymotrypsin were not affected by the fibre level in the diet. Total activity of trypsin on the LP, MP, and HP diets was similar but chymotrypsin activity was greater (P<0.01) on the HP than on the LP and MP diets. The amino acid composition of bile-pancreatic secretions was not affected by the diet composition.