A prospective investigation of the diagnostic value of imaging procedures, computed tomography (CT) and endoscopic retrograde pancreatography (ERP) in comparison with the exocrine pancreatic function test, was done in 109 patients with chronic pancreatitis. The sensitivity of the secretin-ceruletide test (SC) proved to be 87% as compared with 89% for ERP and 78% for CT. The severity of morphological lesions noted in ERP and CT, shows a significant correlation to the degree of the exocrine functional impairment (p less than 0.001). 75% of patients with chronic pancreatitis had corresponding functional and ductal changes in advanced-stage disease, while only 47% of the patients with severe pancreatic insufficiency had CT changes of a corresponding degree. ERP lesions such as ductal obstruction and marked duct dilatation, and CT alterations such as atrophy and ductal dilatation, are almost always coupled with severe pancreatic insufficiency in chronic pancreatitis. Calcific lesions demonstrated by CT are also found in less advanced stages of exocrine insufficiency. Discrepancies between functional and morphological alterations were remarkable in "early" stages of the disease.