Unexplained right upper quadrant symptoms have often been attributed to bile duct dyskinesia. In this study we evaluated the pressure profile of the sphincter of Oddi in 10 patients with recurrent episodes of right upper quadrant pain, intermittent mild transaminasemia, and a normal pancreatobiliary tract. Nine healthy volunteers served as control. A triple-lumen catheter with an external diameter of 1.7 mm and recording sites at 2-mm intervals was introduced into the papilla through the endoscope. Ductal pressure, basal sphincter of Oddi pressure, and the amplitude and propagation direction of the phasic contractions of the sphincter were determined in patients and subjects. All measurements were performed relative to duodenal pressure, which was taken as zero. There was no significant difference between patients and subjects in the amplitude and frequency of phasic contractions of sphincter of Oddi. In contrast, the patients demonstrated a higher sphincter of Oddi pressure (p less than 0.005) and increased proportion of retrograde propagation direction of phasic contractions (p less than 0.01). It is concluded that a subpopulation of patients with unexplained abdominal pain demonstrated abnormal pressure profile of the sphincter of Oddi.