We have studied the degree of pancreatic secretory alterations assessed by secretin-cerulein test (S-C) in relation to various morphological changes detected by real-time ultrasonography (US) in 42 patients affected by chronic pancreatitis. Exocrine insufficiency was found in 41 patients (97.6%), while morphological alterations were detected in 32 (76.1%). In the 10 patients with normal US, a mild or moderate exocrine insufficiency was present. Significant negative linear correlations of decreasing volumes of duodenal aspirate (r = 0.528, p less than 0.001) and output of bicarbonate (r = 0.635, p less than 0.001), lipase (r = 0.583, p less than 0.001), and chymotrypsin (r = 0.592, p less than 0.001) were found with increasing ultrasonographic alterations. However, a wide overlap was found in the secretory behavior in the various categories of change as determined by ultrasound. Hence, the attempt to predict exocrine function on the basis of morphological alterations proved unsuccessful.