Seven patients who had elevated amylase activity in the bile at cholecystectomy and seven normal volunteers were prospectively examined by secretin-stimulated dynamic MRCP. Thirty-five consecutive MR cholangiopancreatograms were acquired at intervals of approximately 10 sec after secretin injection; the acquisition time was 4 sec per image. In all normal volunteers, no apparent signal intensity (SI) changes were noted in the intra- and extrahepatic ducts. Of the 7 patients, the extrahepatic duct showed a sequential SI increase from downstream to upstream in 6; its caliber increased subsequent to pancreatic fluid secretion in 5; and duodenal filling grade tended to be lower in the patients (p < 0.01). These findings were thought to be suggestive of pancreaticobiliary reflux.