Chronic acalculous gallbladder and chronic acalculous biliary disease are considered functional hepatobiliary diseases. Cholescintigraphy provides physiologic imaging of biliary drainage, making it ideally suited for their noninvasive diagnosis. For chronic acalculous gallbladder disease, calculation of a gallbladder ejection fraction during sincalide cholescintigraphy can confirm the clinical diagnosis and has become a common routine procedure in many nuclear medicine clinics. Published data generally confirm a high overall accuracy for predicting relief of symptoms with cholecystectomy. However, data also exist suggesting it is not useful. The discrepant results probably are caused by the various different methodologies that have been used for sincalide infusion. Proper methodology of sincalide infusion is critical for providing accurate reproducible results, minimizing false positive studies, and preventing adverse side effects. The most common causes for the postcholecystectomy pain syndrome are partial biliary obstruction secondary to stones or tumor and sphincter of Oddi dysfunction. The latter is a partial biliary obstruction at the level of the sphincter. This has long been considered a functional hepatobiliary disease because of the lack of anatomical abnormalities. Sphincterotomy is the present treatment; however, diagnosis requires invasive procedures, such as endoscopic retrograde cholangiopancreatography and sphincter of Oddi manometry, which has a high complication rate and is not widely available. The unique ability of cholescintigraphy to image biliary drainage allows noninvasive diagnosis. Different methodologies have been reported, many with good overall accuracy. Various pharmacologic interventions and quantitative methodologies have been used in conjunction with cholescintigraphy to enhance its diagnostic capability. Further investigations are needed determine the optimal methodology; however, cholescintigraphic methods have already a clinical role in the diagnosis of sphincter of Oddi dysfunction and will be used increasingly in the future.