This study was prospectively carried out to evaluate the frequency and clinical significance of pancreatic impairment in the course of chronic inflammatory bowel disease (CIBD). Twenty-seven patients affected by ulcerative colitis or Crohn's disease were submitted to a secretin-cerulein test, oral glucose test (OGT) and to indirect immunofluorescence (IFL) for detection of autoantibodies against exocrine and endocrine tissue. A bicarbonate plus enzyme or only an enzyme insufficiency was found in 11/27 patients, whereas isolated lipase decrease was observed in 18 subjects. In the results of the OGT and the indirect IFL test there was no difference between patients and controls. These data demonstrate that pancreatic impairment is a far more frequent occurrence than generally recognized in clinical practice. The decrease of lipase secretion could worsen the consequences of malabsorption in Crohn's disease of the small intestine. Therefore we think that a pancreatic assessment is advisable, at least in Crohn's disease patients with steatorrhea.