With the introduction of multidetector row computed tomography (MDCT), CT is being considered a potential diagnostic method for patients with acute gastrointestinal (GI) bleeding. On arterial phase MDCT images, active GI bleeding is typically identified as a focal area of high attenuation within the bowel lumen, which represents a collection of contrast material that has been extravasated in association with arterial bleeding. Additional CT findings suggestive of acute GI bleeding are focal dilatation of fluid-filled bowel segment noted on contrast-enhanced CT and acute hematoma on unenhanced CT. In addition to detection of active bleeding, an advantage of contrast-enhanced MDCT is the ability to demonstrate morphologic changes in the GI tract, which could suggest specific conditions that cause acute GI bleeding such as intestinal tumors. Arterial phase contrast-enhanced MDCT is rapid, noninvasive, and accurate in detecting and localizing sites of bleeding in patients with acute GI bleeding. Contrast-enhanced MDCT may be a promising diagnostic option in patients with acute GI bleeding.