BACKGROUND: The pathology of non-alcoholic chronic pancreatitis has not yet been sufficiently studied. AIMS: To identify the major changes of pancreatic tissue in patients surgically treated for non-alcoholic chronic pancreatitis. PATIENTS: Pancreatectomy specimens from 12 patients with non-alcoholic chronic pancreatitis, including four patients with autoimmune or related diseases (Sjögren's syndrome, primary sclerosing cholangitis, ulcerative colitis, and Crohn's disease), were reviewed. METHODS: Morphological changes were studied histologically and immunohistochemically (to type inflammatory cells) and compared with the pancreatic alterations found in 12 patients with alcoholic chronic pancreatitis. RESULTS: In patients with non-alcoholic chronic pancreatitis, with or without associated autoimmune or related diseases, pancreatic inflammation particularly involved the ducts, commonly resulting in duct obstruction and occasionally duct destruction. None of these features was seen in alcoholic chronic pancreatitis which, however, showed pseudocysts and calcifications. CONCLUSION: The pancreatic changes in patients with non-alcoholic chronic pancreatitis clearly differ from those with alcoholic chronic pancreatitis. The term chronic duct destructive pancreatitis is suggested for this type of pancreatic disease.