We performed a bentiromide test in 25 patients with chronic pancreatitis and 7 normal controls to evaluate pancreatic exocrine function, and compared the test results of patients with their endoscopic retrograde pancreatography(ERP) findings. The cumulative 6-hour recovery rate of para-aminobenzoic acid(PABA) in the urine was significantly lower in patients with chronic pancreatitis(55.8 ± 24.2%) than in controls(82.0 ± 10.0%). Among 25 patients with chronic pancreatitis, however, 7 patients showed normal recovery rates of PABA. Pancreatograms of the patients represented 4 mild changes, 5 moderate changes, and 16 marked changes. The average 6-hour recovery rates of PABA of the groups were 56.9 ± 21.6%, 78.4 ± 10.5%, and 47.2 ± 23.7%, respectively. Urinary PABA recovery rates were found subnormal as follows: 3(75%) in the mild changes group; 1(20%) in the moderate changes group; and 14(87.5%) in the marked changes group. We found hardly any correlation between the degree of functional impairment and the changes noted by ERP. These findings suggest that both the pancreatic function test and morphologic study are required to evaluate the degree of functional impairment in patients with chronic pancreatitis.