Abstract: OBJECTIVE To explore the levels of procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP) and T lymphocytes of the acute cerebral infarction patients with pulmonary infection. METHODS Totally 45 patients with acute cerebral infarction who were treated in Ling'an District People's Hospital from Feb 2017 to Jun 2018 were chosen as the control group, meanwhile, 45 acute cerebral infarction patients with pulmonary infection were assigned as the study group. The score on the National Institutes of Health Stroke Scale (NIHSS), Mini-Mental State Examination (MMSE) score, neutrophil CD₆₄ level, hs-CRP level, PCT level and white blood cell (WBC) counts were observed and compared between the two groups. Pearson correlation analysis was performed to explore the correlation between the pulmonary infection in the acute cerebral infarction patients and the neutrophil CD₆₄, hs-CRP, PCT and WBC. RESULTS The MMSE score of the study group was significantly lower than that of the control group, while the NIHSS of the study group was significantly higher than that of the control group (P<0.05). The levels of neutrophil CD₆₄, hs-CRP, PCT and WBC of the study group were significantly higher than those of the control group (P<0.05), the levels of T lymphocytes CD₃⁺, CD₄⁺ and CD₄⁺/CD₈⁺ of the study group were significantly lower than those of the control group, while the levels of T lymphocytes CD₈⁺ and CD₄⁺CD₈⁺ of the study group were significantly higher than those of the control group (P<0.05). The Pearson correlation analysis showed that the pulmonary infection in the patients with acute cerebral infarction was positively correlated with the neutrophil CD₆₄, hs-CRP and PCT (r=0.625,0.234,0.943;P＜0.05,P＜0.05,P＜0.05). CONCLUSION The levels of PCT, hs-CRP and CD₆₄ of the acute cerebral infarction patients with pulmonary infection are high, and the positive rate of joint detection of the three indexes is high.