OBJECTIVE Endoscopic sphincterotomy (ES) of the sphincter of Oddi (SO) has been accepted as an effective method in extraction of common bile duct stones in postcholecystectomy patients. The purpose of this study was to examine the completeness of the performed ES and observe the post sphincterotomy pancreatic duct sphincter (PDS) activity using endoscopic manometry. METHODS Activity of the sphincter of Oddi was examined in 15 sphincterotomized patients using endoscopic manometry one to 2.5 years after endoscopic sphincterotomy for choledocholithiasis. RESULTS In eight patients absence of choledochoduodenal gradient, baseline pressure and the sphincter of Oddi phasic activity up to 2.5 years after endoscopic sphincterotomy indicated a complete sphincterotomy. In seven patients with incomplete endoscopic sphincterotomy, manometry exhibited either a lower choledochoduodenal gradient and baseline pressure without phasic activity of the sphincter of Oddi (three patients), a sphincter of Oddi activity without choledochoduodenal gradient (one patient), or a complete restitution of the sphincter of Oddi activity 1 to 2 years after endoscopic sphincterotomy (three patients). In five patients, with complete endoscopic sphincterotomy, measurements of pancreatic sphincter activity showed lower values of the pancreatic ductal pressure and baseline pressure, while the pancreatic sphincter phasic activity was equal to that found in the control group. CONCLUSIONS Endoscopic manometry is method which enables us to test the completeness of endoscopic sphincterotomy and to follow the restitution of the phasic contractile function of the sphincter. Manometric findings reveal pancreatic sphincter in most patients as a separate sphincteric entity, the function of which is reduced but not eliminated by a complete endoscopic sphincterotomy.