ObjectiveTo systematically assess risk factors for pulmonary infection in patients after tracheal intubation under general anesthesia.MethodsLiteratures published between the establishment of database and September 15, 2017 were retrieved from PubMed, China National Knowledge Infrastructure (CNKI),  Chinese Biology Medicine (CBM) database, Wanfang database (Wanfang), and VIP database, data about pulmonary infection in patients after tracheal intubation under general anesthesia were collected. Literatures were screened, extracted, and evaluated according to inclusion and exclusion criteria by two reviewers, Metaanalysis was conducted using RevMan 5.3 software.ResultsA total of 19 literatures were included for analysis. Metaanalysis showed that the following factors were associated with occurrence of pulmonary infection in patients after tracheal intubation under general anesthesia: age, smoking, emergency surgery, underlying disease, duration of tracheal intubation, duration of general anesthesia, method of intubation, depth of intubation, proficiency of intubation(whether intubation was repeated), indication of extubation, and delay of extubation. The combined OR values and 95%CI of each factor analysis were 3.19(2.58-3.95), 2.43(1.55-3.82), 2.45 (1.42-4.24), 4.85(2.36-9.94), 4.96 (2.08-11.84), 3.33 (1.15-9.70), 1.49(1.06-2.09), 4.67(2.74-7.96), 2.52 (2.14-2.98), 2.23(1.90-2.61), and 3.91(3.18-4.81), respectively.ConclusionIt is important to grasp strictly the indication of general anesthesia for tracheal intubation, standardize management of tracheal intubation and extubation after anesthesia resuscitation, seize the opportunity to remove tracheal catheter, and reduce risk of postoperative infection.