A number of techniques have been developed to control active upper gastrointestinal tract bleeding. These include thermal devices such as the laser, heater probe, and bipolar circumactive probe (BICAP). Although these devices have proved effective, they vary in cost and at times are cumbersome to use. A simple, inexpensive, readily available means of treating active bleeding from the gastrointestinal tract is injection of the lesion with a sclerosing substance. This method has proved helpful in stopping variceal hemorrhage, and the simplicity of the equipment and procedure makes it an outstanding candidate therapy for treating other causes of hemorrhage. Although the method is not well known in the United States, it has been applied in Japan and Europe. Most studies so far have been uncontrolled, but in over 700 patients reported in the world literature, effective initial hemostasis has been achieved in about 90% of patients overall. Success rates have been somewhat dependent on the site and rate of bleeding. No deaths have been reported from the procedure. We review the current status, techniques, and types of sclerosing agents and provide a detailed analysis of results of injection sclero-therapy. We propose that although the technique is simple, the effectiveness and routine application to the patient with upper gastrointestinal hemorrhage await careful controlled studies and comparison with other available hemostatic methods.