Objective To understand the epidemiological characteristics and trends of postoperative pneumonia (POP) in tertiary general hospitals in Jiangsu Province, and provide theoretical basis for carrying out targeted prevention and control measures. Methods Surgery patients from 22 tertiary general hospitals in 12 cities in north, central, and south of Jiangsu Province from January 1, 2022 to December 31, 2023 were chosen as studied subjects, occurrence of POP was analyzed and compared. Results A total of 848 274 surgical procedures were performed in 22 hospitals, and 3 606 cases of POP occurred, with an incidence of 0.43%. The incidence in 2023 was 0.37%, which was lower than that in 2022 (0.49%), with statistically significant difference (P<0.001). The top three departments with high incidence of POP were neurosurgery (6.71%), cardiothoracic surgery (2.91%), and general surgery (0.77%). Among hospitals of different grades, the incidence of POP in tertiary first-class hospitals was 0.44%, which was higher than that in other tertiary hospitals (0.37%). There was no statistically significant difference in the incidence of POP between municipal and district/county hospitals (P>0.05). The incidence of POP in hospitals with a bed: infection control full-time staff ratio<200∶1 was lower than that in hospitals with the ratio ≥200∶1 (0.39% vs 0.47%, P<0.001), while the incidence of POP in hospitals with a proportion ≥30% of full-time staff being doctors was higher than that in hospitals with a proportion ＜30% (0.45% vs 0.36%, P<0.001). The incidence of POP in male patients was higher than that in female patients (0.62% vs 0.26%, P<0.001). The incidence of POP in elderly patients aged ≥65 was higher than that in patients aged <65 (0.73% vs 0.26%, P<0.001). A total of 2 667 strains of infectious pathogens were detected, with the top three being Acinetobacter baumannii,Klebsiella pneumoniae, and Pseudomonas aeruginosa, accounting for 28.95%, 22.72%, and 15.45%, respectively. The detection rates of carbapenem-resistant Acinetobacter baumannii (CRAB), carba-penem-resistant Klebsiella pneumoniae (CRKP), and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were 60.75%, 21.45%, and 32.28%, respectively. The detection rate of CRKP decreased in 2023 compared with 2022, with statistically significant difference (P<0.05). Conclusion The overall incidence of POP in tertiary general hospitals in Jiangsu Province is relatively low, but there are significant differences among different hospitals. Therefore, perioperative prevention and control measures should be carried out based on the epidemiological characteristics of patients.