The efficacy and safety of transcatheter arterial embolization with n-butyl cyanoacrylate (NBCA-TAE) for Forrest I gastroduodenal ulcer bleeding were evaluated from the experience of 26 patients who underwent NBCA-TAE. Shock indices prior to and immediately after NBCA-TAE were compared to determine changes in hemodynamics. Days to Forrest type Ⅲ, as assessed by follow-up endoscopy, was used as an indicator of the healing process. Immediate hemostasis was achieved in all the patients, and the shock index significantly (p<0.001) improved from before (1.09±0.088) to immediately after NBCA-TAE (0.68±0.031). Sequential mucosal healing processes were observed in all the patients, and the number of days to Forrest type Ⅲ was 9.0±3.8. NBCA-TAE is an effective and safe method for the control of gastroduodenal ulcer bleeding, in terms of contribution to hemodynamics and healing process of the gastroduodenal mucosa. However, understanding the behavior of NBCA within the circulation and adequate administration techniques are necessary.