Abdominal pain in patients with chronic pancreatitis has been related to an increase in plasma cholecystokinin (CCK) levels. The aim of the study was to disclose the relation of the altered response with the low intraduodenal bile acids levels found in these patients. Twenty patients with chronic pancreatitis were classified into groups I (n = 11) and II (n = 9) according to the presence or absence of pain. Intraduodenal trypsin and bile acids concentrations and plasma CCK levels were measured before and 30, 60, and 90 min after a test meal. Comparisons between values in both groups were carried out. Correlation of intraduodenal trypsin and bile acids with plasma CCK was analyzed. Patients with pain exhibited significantly lower intraduodenal trypsin levels at 30 and 90 min and lower basal and postprandial intraduodenal bile acids levels than patients without pain. In patients with pain, basal and postprandial plasma CCK levels were significantly higher than in patients without pain. A negative correlation was demonstrated between intraduodenal bile acids and plasma CCK. In patients with chronic pancreatitis and pain, a reduction in intraduodenal postprandial trypsin and basal and postprandial bile acids concentrations, as well as an increase in basal and postprandial plasma CCK levels, was encountered. A negative correlation between intraduodenal bile acids and plasma CCK concentrations was detected that may be implicated in the pathogenesis of pain.