Objective To analyze the occurrence of postoperative pneumonia (POP) in a tertiary general first-class hospital in Shanghai, and provide basis for strengthening the implementation of POP prevention and control measures for the target population. Methods The real-time monitoring data of healthcare-associated infection (HAI) from 2017 to 2023 were retrospectively surveyed. The occurrence of POP in all surgical patients (including minimally invasive interventional surgery) were analyzed. Results A total of 701 postoperative patients had POP. The incidence of POP was 0.30%. Incidence of POP was higher in male patients than in female patients(0.48% vs 0.15%), in 65-year-old-population than in <65-year-old-population(0.58% vs 0.17%), and in elective surgery than in emergency surgery (0.35% vs 0.27%), differences were statistically significant (all P<0.05). The interval from postoperative time to POP occurrence in 701 POP patients was 6 (4, 10) days, with emergency surgery patients developing POP later than elective surgery (7［4,11］ days vs 6［3,10］ days), and difference was statistically significant (P<0.05). The top five departments with higher incidences of POP were neurosurgery (5.84%), cardiac surgery (4.01%), thoracic surgery (1.92%), abdominal surgery (0.74%), and minimally invasive intervention (0.17%). Incidence of POP in emergency neurosurgery was higher than that in elective neurosurgery (9.71% vs 2.14%), while incidences of POP in elective cardiac surgery and thoracic surgery were both higher than emergency surgery (5.09% vs 2.93%, 2.46% vs 0.58%, respectively), differences were all statistically significant (all P<0.05). A total of 675 strains of pathogens were detected from 701 POP patients, with Gram-negative bacteria being the major pathogens (n=520,77.04%). The predominant detected pathogens were Acinetobacter baumannii (n=119), Pseudomonas aeruginosa (n=116), Staphylococcus aureus (n=108), Klebsiella pneumoniae (n=104), and Stenotrophomonas maltophilia (n=47). Conclusion In the prevention and control of perioperative infection, the key populations for POP prevention and control should be males and those aged ≥65 years old, and the key departments should be neurosurgery, cardiac/thoracic surgery, and abdominal surgery. Minimal invasive surgery also has the risk of POP, which should be paid more attention.