Objective Objective To investigate the clinical characteristics and risk factors of elderly patients with acute ischemic stroke complicated with pulmonary infection. Methods A retrospective study was conducted on 1 113 elderly patients with acute ischemic stroke admitted to the department of neurology, Shenzhen Second People's Hospital from July 2017 to October 2019. Among them, 108 patients with stroke complicated with pulmonary infection were included in the infection group and 1 005 patients without concurrent pulmonary infection were included in the control group. The clinical data of the two groups were analyzed by single factor comparison, and the risk factors for pulmonary infection were analyzed by logistic multiple factor regression analysis. Results Single factor analysis showed there were statistically significant differences between the two groups in age (especially elderly patients), length of stay in hospital, atrial fibrillation, history of cerebral infarction, chronic pulmonary disease, dysphagia, slurred speech, and disturbance of consciousness (P <0.05). Multi-factor logistic regression analysis showed that old age (≥80 years old), length of stay in hospital, history of cerebral infarction, dysphagia, slurred speech, and disturbance of consciousness were closely related to pulmonary infection in elderly patients with acute ischemic stroke. Conclusion The independent risk factors of acute ischemic stroke complicated with pulmonary infection in the elderly mainly include old age (≥80 years old), length of stay in hospital, history of cerebral infarction, dysphagia, slurred speech and disturbance of consciousness, which should be paid more attention to clinically.