A case of CT demonstration of a bleeding gastric ulcer is presented, in a patient with confusing clinical manifestations. Abdominal CT was performed without oral contrast medium administration, and showed extravasation of intravenous contrast into a gastric lumen distended with material of mixed attenuation. It is postulated that if radiopaque oral contrast had been given, peptic ulcer bleeding would probably have been masked. CT demonstration of gastric ulcer bleeding, may be of value in cases of differential diagnostic dilemmas.