Stroke-associated pneumonia (SAP) is a pulmonary infection that complicates the acute and post-stroke phases of stroke patients. Stroke-associated pneumonia is an independent risk factor for increased in-hospital mortality and poor discharge prognosis. Stroke-associated pneumonia is an important cause of deterioration, poor prognosis and death in stroke patients. Stroke-associated pneumonia not only seriously affects the prognosis of patients, but also prolongs hospitalization and increases hospitalization costs, so standardized prevention and treatment should be carried out. Stroke has a high morbidity, mortality, disability and recurrence rate. The average annual incidence of stroke worldwide is about 200/100,000, resulting in approximately 5.5 million deaths. In China, there are more than 2 million new cases of stroke each year, of which about 20% are hemorrhagic strokes and 80% are ischemic strokes, and more than 1.5 million deaths each year, with a mortality rate of about 150/100,000. Stroke is the leading cause of disability and the second leading cause of death in both urban and rural areas. According to the literature, the acute mortality rate of cerebral hemorrhage is about 12%. When analyzing the causes of death, central failure is about 29.45% and pneumonia accounts for 28.08%, second only to central failure. Stroke-associated pneumonia is also the most common comorbidity in patients with acute ischemic stroke, with an incidence of 10% to 47%, and pneumonia accounts for 34% of deaths. Clinical observations and literature suggest that there are two main risk factors for the development of stroke-associated pneumonia, in addition to the type of stroke. These include advanced age, coma, aspiration or vomiting, bed rest, swallowing disorders, atrial fibrillation, chronic cardiac insufficiency, hypoalbuminemia, underlying lung disease, and pre-existing infections. hospitalization and prolonged ICU stay. It is worth noting that surgical treatment, including intervention, significantly improves the prognosis of stroke patients, but general anesthesia procedures increase the incidence of stroke-associated pneumonia. The pathophysiological mechanisms that cause the development of stroke-associated pneumonia are complex. The direct damage of stroke and the secondary increase in intracranial pressure can affect the central function, causing impaired consciousness, dysphagia and loss of cough reflex, pulmonary insufficiency, decreased ventilation, and even pulmonary stasis, pulmonary edema, acute respiratory distress syndrome and respiratory failure. In addition, increased sympathetic excitability mediated by advanced age or post-stroke hypoimmunity reduces the patient’s ability to resist disease. Once stroke associated pneumonia occurs, it can in turn affect the treatment and recovery of stroke patients. The impact of pneumonia on stroke patients is multifaceted. First, it is hypoxia, which leads to secondary brain damage and aggravates brain edema and central damage; second, it is stress; and third, it causes systemic inflammatory response syndrome, which leads to an imbalance of inflammatory and anti-inflammatory responses, thus inducing brain-derived multi-organ insufficiency. The vicious circle of stroke and pneumonia inevitably increases the risk of death and disability; while stroke-associated pneumonia can lead to prolonged hospitalization and delayed discharge of stroke patients; and significantly increases healthcare costs. Stroke-associated pneumonia has a specific pattern of evolution. Stroke-associated pneumonia can occur on the day of stroke onset. Decreased consciousness and severe facial paralysis are important predictors of stroke-associated pneumonia. The clinical features of stroke-associated pneumonia are as follows: ① The presentation is varied. It often starts as aspiration pneumonia or fallout pneumonia; inhalation can be pharyngeal secretions, subsonic secretions or regurgitated gastric contents, mostly containing food residues, gastric acid and bacteria; early presentation can be characterized as community-acquired pneumonia or hospital-acquired pneumonia, ventilator-associated pneumonia can occur in mechanically ventilated individuals, and the posterior phase is often characterized by medical care-associated pneumonia. The pathogens are diverse. mixed infections with G-bacteria as the main cause are common. The pathogenic bacteria of stroke-associated pneumonia vary with the course of the disease, mainly Streptococcus pneumoniae and Haemophilus influenzae in the early stage of the disease; G-bacteria take the first place in the middle stage, followed by G+ cocci such as Staphylococcus aureus, and anaerobic bacteria are also common; the common causative agents of G-bacterial infections are Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli and Proteus mirabilis; the late stage often shows mixed infections and fungal infection. ③ Clinical manifestations are atypical. Especially in advanced age and occult misaspiration, it is often hidden unresponsive early-onset pneumonia or fallout pneumonia, which is very easy to delay the diagnosis and treatment. ④The condition is easily recurrent. ⑤ The condition changes rapidly and is easily complicated by pulmonary edema, septic shock, acute respiratory distress syndrome and respiratory failure. The diagnosis of stroke-associated pneumonia is difficult. Factors such as patient coma, hyporesponsiveness, inability to cough up sputum, and difficulty in detecting lesions on bedside chest radiographs make the Clinical Pulmonary Infection Scoring System (CPIS) insensitive. Chest CT examination, smear and culture of airway secretions, and monitoring of peripheral blood leukocytes, calcitoninogen, oxygenation index, blood lactate value and alkali residual should be done as an option for early diagnosis of stroke-associated pneumonia whenever conditions permit. Proper evaluation of the patient’s condition, causative organism and appropriate grading of treatment are the key points in the diagnosis and management of stroke-associated pneumonia. Special tips for oxygenation index.