Biliary dyskinesia is a functional disorder of the biliary tract, especially spasm of the sphincter of Oddi(SO). It is sometimes impossible to differentiate patients with true biliary dyskinesia from those patients with papillary stenosis, which is a structural narrowing of part or all of the SO segment. Because of the difficutly in clearly separating these two clinical entities, this syndrome have been eailed SO dysfunetion. Classically, the patient with SO dysfunction is frequently a female between 20 and 50 years of age with a history of recurrent biliary-type pain. the discomfort is occasionally associated with nausea, vomiting, eructation and may be exacerbated by food intake. The diagnosi of SO dysfunction has been suggested by the symptom complex, exclusion of anatomic biliary tract disease, and finally by the pharmacologic provocation and relief of pain. Rer.ent developement in recording instrument such as biliary manometry allows the accurate evaluation of the motor activity of. the SO. In the treatrnent of SO dysfunction, endoscopic or surgical sphincterotomy has been used to abolish the sphincter mechanism, and pharmacologic means such as nifedipine may have a possible therapeutic rele. We report a case of biliary II type of SO dysfunction diagnonsed by biliary manornetry. The patient had sufferd from billiary-type pain for 5 years, and had normal liver function tests, delayed drainage of ERCP contrast beyond 45 minutes, and a dilated common bile duct. SO manometric pressure measurement revealed a signifieant elevation of SO basal pressure. The patient was treated by endoscopic sphinctecrotomy with a favorable manometric and symptomatic response.