Results of the SPT and the ERCP staged for their severity were compared in 202 patients. The correlation between both investigations was significant (p < 0.001); however, ERCP showed significantly more severe changes (p = 0.04). Furthermore, we found that 129 (64%) patients had parallel SPT and ERCP results, matching in all four gradings of severity. Forty-three (21%) patients had abnormal results for both SPT and ERCP, but the severity gradings did not parallel. Finally, 30 (15%) patients showed totally nonparallel results, a normal SPT and abnormal ERCP, or vice versa. Abnormal ERCP but normal SPT results were found in 23 of these 30 patients (group 1), and normal ERCP but abnormal SPT results in the seven remaining cases (group 2). In the first group, more patients had a history of acute pancreatitis compared to the second group (19 vs. one, p < 0.005). Based on medical history, laboratory and functional test results, and other morphological tests, chronic pancreatitis was diagnosed in two of 23 patients in group 1 and in all seven patients in group 2. Follow-up interviews (86 +/- 54 months) were possible in 20 of the remaining 21 patients in group 1 and showed definite chronic pancreatitis in one and probable chronic pancreatitis in another two of them, whereas in the other 17 patients no symptoms of acute pancreatitis or abdominal pain suggestive of chronic pancreatitis had occurred. In conclusion, both SPT and ERCP should be used to complement each other when chronic pancreatitis is suspected. ERCP seems to over-diagnose the disease since duct changes may only reflect scars after severe acute pancreatitis, or old age, and are not necessarily a sign of chronic pancreatitis. SPT seems to diagnose chronic pancreatitis with more reliability.