AbstractLaser therapy is theoretically more advantageous than endoscopic techniques such as diathermy in the treatment of alimentary bleeding primarily because the bleeding point is not directly touched or handled during therapy and the amount of energy dissipated in the surrounding tissue is more easily controlled. Only Argon and Neodymium‐Yttrium Aluminum Garnet (Nd Yag) laser beams can be passed down flexible wave guides suitable for endoscopic use in clinical gastroenterology. The Argon laser has been used by several groups for the treatment of patients with upper gastrointestinal bleeding. Success has been achieved in 80 to 95 percent of patients. Randomized trials comparing laser therapy to other modalities or to conservative, nonendoscopic therapy have in general suggested a greater benefit and lower incidence of rebleeding following laser application. Prospects for the utilization of lasers in patients with gastrointestinal bleeding depend crucially on the correct execution of randomized controlled trials currently in progress.