OUR BELIEF is that the future success in the diagnosis of internal biliary fistula lies not in roentgenologic examination exclusively but more in evaluation of the pathologic antecedents that accompany the biliary fistula. With more emphasis placed on clinical study of cases of biliary disease, a greater number of biliary fistulas will be recognized earlier, thus minimizing future complications, and with more attention to the preoperative care the present mortality rate following operations on internal biliary fistulas will be reduced. Spontaneous internal biliary fistulas are infrequent. The majority result from infections and calculi in the gallbladder or are caused by a perforative ulcer or a malignant growth of the stomach or bowel. According to the literature, in only 108 cases have internal biliary fistulas been recognized preoperatively, and all have been diagnosed by roentgenologic examination. Of this number, including our case, in only 12 cases has diagnosis been made by