Local hemostatic agent Haemoblock was used for improvement of the visualization of the source of gastroduodenal bleeding. Intraorgan application of Haemoblock allows endoscopists to identify significant features of biotissue defects and to optimize further actions to achieve reliable hemostasis and to prevent secondary bleeding. Clinical study of the diagnosis and treatment of 84 patients with gastroduodenal bleeding was presented. Preliminary usage of Haemoblock allows to identify the source of bleeding in 98 % cases, to improve intra organ interventions for getting reliable hemostasis and to prevent secondary bleeding in specified localizations.