The combined diagnostic modalities using abdominal ultrasound, endoscopic ultrasound and endascopic retrograde cholangiopancreatogram are useful for the diagnosis of gall bladder disease. But, these diagnostic methods have limitations for the detection of early flat-type gallbladder cancer. To cope with these problems, double contrast study of gallbladder disease is being recently used to diagnose the flat-type cancer of gallbladder in Japan. Herein we report a case of chronic cholecystitis confirmed histologically and assisted by double contrast method of gallbladder, which was diagnosed as a gallbladder polyp by abdominal sonogram at first. The method requires the cystic duct cannulation and placement of the catheter to the gallbladder. And then Barium sulfate and CO2 are injected through the catheter. The patient didnt experience any complication during and after this procedure except for hyperamylasemia. After the simple cholecystectomy, he improved completely. In conclusion, double contrast study of gallbladder can be useful in the diagnosis of the gallbladder disease and compensate for the other dignostic tools. (Korean J Gastrointest Endosc 18: 117-121, 1998)