Background: It is common for high-risk, non-variceal upper gastrointestinal bleeding (NUGIB) patients coexisting anemia, but the role of anemia on the prognosis of endoscopic intervention is not clear. The aim of this study was to assess the impact of hemoglobin level on outcomes of endoscopic intervention in high-risk NUGIB patients. Methods: A retrospective study was performed on high-risk (Glasgow-Blatchford score ≥7) NUGIB patients who underwent endoscopic intervention within 24h of presentation. Patients were divided into three groups based on hemoglobin level before intervention: severe (<7g/dl), moderate (7g/dl ≤hemoglobin <9g/dl) and mild (≥9g/dl) group. Outcomes included mortality, length of ICU stay, re-bleeding rate, procedural adverse events, length of hospital stay, adverse events and transfusion requirement. Results: A total of 156 patients received endoscopic intervention were identified, 88 in the severe group, 45 in the moderate group, and 23 in the mild group. The total mortality rate in 45 days was 2%, and the re-bleeding rate was 21%. There was no significant difference in mortality, re-bleeding rate or length of ICU stay among the three groups. The average days of hospitalization in the severe group was significantly longer than that of the moderate group (13 vs 8, P < 0.05). No adverse events occurred. Low hemoglobin level was a predictor for more red-cell transfusion (OR=5.94, 2.69-13.11) and plasma transfusion (OR=2.34,1.21-4.51). Conclusions: Anemia does not affect the mortality and rebleeding of endoscopic intervention in high-risk NUGIB patients, but is associated with more transfusion and longer hospitalization.