Objective: To investigate the correlation between post-stroke pneumonia and outcome in patients with acute brain infarction. Methods: Consecutive acute cerebral infarction patients who were hospitalized in Department of Neurology, Jinan Military General Hospital were prospectively recruited from August 2010 to August 2014. The baseline data including age, sex, the National Institute of Health Stroke Scale (NIHSS) scores, type of Oxfordshire Community Stroke Project (OCSP: total anterior circulation infarct, partial anterior circulation infarct, posterior circulation infarct and lacunar infarct), fasting blood glucose etc. after admission were recorded. Post-stroke pneumonia was diagnosed by treating physician according to criteria for hospital-acquired pneumonia of the Centers for Disease Control and Prevention. Recovery was assessed by modified Rankin Scale (mRS) 180 days after stroke by telephone interview (mRS≤2 reflected good prognosis, and mRS>2 reflected unfavorable prognosis). Multinominal Logistic regression analysis, Kaplan-Meier curve and log rank test were used. Results: A total of 1 249 patients were enrolled, among them 173 patients were lost during follow-up. A total of 159 patients had post-stroke pneumonia, while 1 090 patients were without post-stroke. Compared with patients without post-stoke pneumonia, patients with post-stroke pneumonia were older (67±13 vs 63±12 years, P=0.000), more severe (NIHSS, 15(14) vs 4(4), P=0.000). Compared with patients without post-stoke pneumonia, more patients with post-stroke pneumonia suffered from heart failure (12.58% vs 3.40%, P=0.000), atrial fibrillation (26.42% vs 8.81%, P=0.000), myocardial infarction (10.06% vs 5.05%, P=0.016), recurrent brain infarction (30.19% vs 22.66%, P=0.045), total anterior circulation infarct type of OCSP (46.54% vs 19.63%, P=0.000), posterior circulation infarct of OCSP (39.62% vs 25.51%, P=0.001); more patients suffered from disorder of consciousness (60.38% vs 9.27%, P=0.000), dysphagia (34.59% vs 19.89%, P=0.000), vomiting (26.42% vs 8.81%, P=0.000), aphasia (35.85% vs 16.61%, P=0.000) since onset. The morbidity of post-stroke pneumonia among patients with unfavorable outcome (29.37%(111/378)) was significantly higher than that among patients with favorable outcome (3.73%(26/698)) (P=0.000). Post-stroke pneumonia was an independent prognostic factor for long-term unfavorable outcome (OR=2.414, 95%CI: 1.336-4.361, P=0.004) and long-term mortality (OR=2.132, 95%CI: 1.229-3.699, P=0.007). According Kaplan-Meier estimation, the cumulative 180 days survival of patients with post-stroke pneumonia was lower than those without post-stroke pneumonia (62.04%(85/137) vs 93.29%(876/939)); Log-rank test: χ2=137.32, P=0.000. Conclusions: Acute brain infarction patients with post-stroke pneumonia are older, more severe; more suffering from heart failure, atrial fibrillation, myocardial infarction; more suffering from disorder of consciousness since onset. Post-stroke pneumonia is an independent prognostic factor for long-term unfavorable outcome and for long term mortality in patients with acute brain infarction.