Since the early 1980s interventions have been used in conjunction with (99m)Tc-iminodiacetic acid (IDA) radiopharmaceuticals in many different clinical situations, eg, to prepare the patient for the study, to reduce the time of a study, to improve its diagnostic accuracy, and to make diagnoses not otherwise possible. Interventions all have underlying physiological rationales. Some of these interventions are as simple as having the patient fast before the study or eat a meal with high fat content. However, most are pharmacologic interventions, eg, morphine sulfate, cholecystokinin, and phenobarbital. Although these are probably the most common interventions used today, numerous other interventions have been used during the years and likely will be in the future. Interventions have aided in the diagnosis of acute cholecystitis, chronic cholecystitis, biliary obstruction, and sphincter of Oddi dysfunction. This review will discuss in detail the interventions commonly is use today and in somewhat less detail many that have been successfully used on an investigational basis and may have some larger role in the future.