A 51-year-old man presented complaining of frequent diarrhea. An ultrasonography and abdominal C T scan revealed a tumor in the tail of the pancreas. An endoscopic retrograde pancreatography revealed contrast medium flowing over the pancreas through the main pancreatic duct. A balloon cathether was then passed into the pancreatic duct, and the scope alone was retracted to the stomach. Maintaining the stomach under endoscopic observation, ICG was injected through the balloon catheter, whereupon it was seen to flow out from two small depressions in the center of a small elevated lesion in the posterior wall of the upper gastm'c co@us. Based on these endoscopic findings, a diagnosis of chronic pancreatitis with an associated pancreato-gastric fistula was made.