Gastronintestinal bleeding remains a major diagnostic problem. Although advances have been made in the medicaland surgical methods of managing gastrointestinal bleeding, the commonly employed techniques of bariumradiography, endoscopy, and angiography may not successfuly localize the site and define the cause ofgastrointestinal bleeding. Two widely available technetium-99m-labeled radiophamaceuticals, sulfur colloid and redblood cells are currently used in the evaluation of patients who are bleeding from the gastrointestinal tract.Surgically confirmed 19 patients with use of 99mTc-sulfur colloid (7 cases ) and 99mTc-RBC(12 cases ) wereretrospectively evaluated. The overall sensitivity of scintigraphy in detection of bleeding and localization ofbleeding site was 68% and 84%, respectively. The authors conclude that bleeding scintigraphy is a safe, sensitive,and non-invasive method as an effective secreening test before performing angiography or surgery.