Objective: To investigate the relationship between hemoglobin levels and prognosis of cerebral infarction in elderly patients aged 75 years and over. Methods: A retrospective analysis of 238 elderly patients (≥75 years old) with cerebral infarction admitted into our hospital from January 2016 to June 2018 was performed. The age, gender, serum creatinine and risk factors for stroke (hypertension, diabetes, dyslipidemia, homocysteine, atrial fibrillation, smoking, drinking), coronary heart disease, previous stroke history, tumor history, National Institutes of Health Stroke Scale (NIHSS) score, hemoglobin, hematocrit and other basic data were recorded. The patients were divided into the group with good prognosis (mRS score ≤ 2) and the group with poor prognosis (mRS score > 2). The relationship between hemoglobin levels and the prognosis of cerebral infarction in elderly patients were analyzed. Results: After 6 months of follow-up, 124 (52.1%, 124/238) stroke patients had a good prognosis, and 114 (47.9%, 114/238) patients had a poor prognosis, including 21 deaths. Anemia at admission (OR=2.433, 95%CI: 1.213-4.591, P=0.011), new-onset anemia after hospitalization (OR=2.615, 95%CI: 1.333-6.521, P=0.043) and the low level of minimum hemoglobin during hospitalization (OR=0.847, 95%CI: 0.671-0.971, P=0.038) were independent risk factors for poor prognosis in elderly stroke patients aged ≥75 years. New-onset anemia after hospitalization (OR=1.015, 95%CI: 1.002-1.027, P=0.022), the low level of minimum hemoglobin during hospitalization (OR=0.801, 95%CI: 0.654-0.981, P=0.027), the decrement of hemoglobin ≥20 g/L (OR=1.342, 95%CI: 1.011-1.763, P=0.000) at reexamination were independent risk factors for the mortality in elderly patients with cerebral infarction. Conclusions Anemia at admission, new-onset anemia after hospitalization, and the low level of minimum hemoglobin during hospitalization are independent predictors for poor prognosis in cerebral infarction patients aged ≥75 years. The decrement of hemoglobin ≥20 g/L after admission is an independent predictor for high mortality in elderly patients with cerebral infarction.