In this study we describe in detail the characteristics of sphincter of Oddi motor function in a large group of healthy subjects. Studies were obtained in 50 healthy volunteers. The findings showed a sphincter of Oddi segment that had a basal pressure of 14.8 +/- 6.3 mm Hg (X +/- SD). Phasic contractions were superimposed on the basal pressure. They had an amplitude of 119.7 +/- 32 mm Hg, a duration of 4.7 +/- 1 sec, and a frequency of 5.7 +/- 1.2 contractions/min. In 40 subjects the propagation sequence of phasic contractions could be evaluated and were simultaneous in 53%, antegrade in 35%, and retrograde in 11% of the waves. In 20 subjects, pressure measurements done at the common bile duct sphincter waves. In 20 subjects, pressure measurements done at the common bile duct sphincter were similar to those obtained at the pancreatic duct sphincter. In 10 subjects, pressure values obtained at the common bile duct sphincter within a week were similar. Our study should help to establish standards for normal manometric values of the sphincter of Oddi and emphasizes the importance of having a healthy volunteer group from which to obtain the normal values of sphincter of Oddi motor function.