BACKGROUND/AIMS: Peptic ulcer bleeding can be treated by endoscopic laser, argon plasma coagulation, heater probe, or electrocoagulation. However, techinical difficulties and significant rebleeding rate after such endoscopic hemostasis, offer some beneficial effect of Alto Shooter(TM) as an adjuvant therapy in active peptic ulcer bleeding. METHODS: Twenty-three patients with active peptic ulcer bleeding were randomized to Alto Shooter(TM) & argon plasma coagulation therapy (ALTO+APC) or argon plasma coagulation therapy alone (APC). Forrest classifications were used to compare the effect of bleeding control. RESULTS: The Forrest classifications in two groups before treatment were Ib (6 patients), IIa (11 patients) in "ALTO+APC", Ib (2 patients) and IIa (4 patients) in "APC". The Forrest classifications of two groups at follow-up endoscopy were Ia (1 patient), Ib (1 patient), IIc (14 patients), III (1 patient) in "ALTO+APC" and IIc (6 patients) in "APC". There was no significant difference in hemostatic effect between "ALTO+APC" (p=0.001) and "APC" (p=0.001) groups. CONCLUSIONS: Alto Shooter(TM) offers no advantage over conventional endoscopic argon plasma coagulation therapy in controlling active peptic ulcer bleeding. Therefore routine addition of Alto ShooterTM treatment may not be recommended after initial successful endoscopic argon plasma coagulation therapy in active peptic ulcer bleeding.