In 78 patients with high-risk bleeding peptic ulcers (either with active bleeding or non-bleeding visible vessel) endoscopic hemostasis by injection of adrenaline and polidocanol was attempted. Sclerotherapy was performed in 70 (90%) patients. Initial hemostasis was achieved in 35 (94.5%) patients with active bleeding, and permanent hemostasis in 61 (87%). Efficacy of injection therapy was significantly lower in ulcers larger than 2 cm (p = 0.001), and in those located on the posteroinferior duodenal wall (p = 0.03). It was not possible to perform endoscopic injection in 8 (10%) patients due to difficulty of access, lesions located mainly high on the lesser gastric curvature and on the posteroinferior duodenal wall. From these results we conclude that endoscopic injection is a very useful technique for the initial treatment of high-risk bleeding peptic ulcer, although the size and anatomical location of the lesions may be a limitation of its use.