In clinical urology the urethral pressure profilometry, developed by Brown and Wickham in 1969, is a well known diagnostical method. To our knowledge this type of investigation was not made in the common bile duct. In order to evaluate this method as an eventual clinical preoperative endoscopic method, especially in disorders of the choledocho-duodenal junction, choledochal pressure profile studies were made in 15 anesthesized mongrel dogs via a duodenotomy. The method was made according to the internationally advised standards of the urethral pressure profilometry. The mean contact basal pressure level in the choledochal duct amounted to 10,9 +/- 2,17 (sem) mm Hg. A statistically significant biphasis pressure elevation was seen in the region of the choledocho-duodenal junction (p less than or equal to 0,05). The mean pressures of the proximal and distal pressure elevation amounted to 59,8 +/- 8,51 (sem) mm Hg and to 54,3 +/- 7,13 (sem) mm Hg. The proximal top was located at 3,68 +/- 0,28 (sem) cm and the distal top at 0,96 +/- 0,07 (sem) cm distance from the orifice of the papilla. The total length of the elevated pressure zone amounted to 5,50 +/- 0,29 (sem) cm and the length of the elevated pressure zone of the distal top was 1,58 +/- 0,10 (sem) cm. These data correlate with the morphological structure of the choledocho-duodenal junction as mentioned in literature and illustrated with X-ray investigation and casts of the distal choledochal lumen. Our data show that with choledochal pressure profilometry pressure and length of the sphincter of Oddi can easily and safely be determined. In combination with endoscopy the technique can be of value in preoperative and postoperative evaluation of the function of the choledocho-duodenal junction.