AIM: To investigate the influencing factors of serum NT-proBNP level in elderly patients with acute myocardial infarction (AMI) after PCI, and to analyze its predictive value for the short-term prognosis of patients. METHODS: A total of 98 elderly patients with AMI in our hospital from May 2020 to August 2022 were selected, all of whom underwent PCI. The level of serum NT-proBNP before and after PCI was detected. The level of serum NT-probNP after PCI was ≥125 pg/mL, and the level of serum NT-probNP after PCI was normal. Univariate analysis of the general data of the elevated NT-proBNP group and the normal group, Lasso regression model was used to screen the screening variables, and Logistic regression was used to analyze the influencing factors of serum NT-proBNP level in elderly AMI patients after PCI. The prognosis recovery of patients with different NT-proBNP and the level of NT-proBNP in patients with different prognosis were compared and analyzed. ROC curve was drawn to analyze the predictive value of NT-proBNP level in patients with short-term prognosis after PCI. RESULTS: Logistic regression analysis showed that the time from onset to PCI, age, left ventricular ejection fraction (LVEF), stroke, number of stents implanted, no recirculation and stent diameter were the influencing factors of serum NT-proBNP level in elderly AMI patients after PCI. The incidence of adverse cardiovascular events (MACE) was 21.43% (21/98) in 98 patients followed up 6 months after surgery, and the incidence of NT-proBNP increased group was 68.00% (17/25), which was significantly higher than that of normal group (5.48% (4/73)) (P<0.05). The level of NT-proBNP in the group with MACE was significantly higher than that in the group without MACE (P<0.05). ROC curve showed that AUC was 0.813 (95%CI: 0.721-0.884), sensitivity and specificity were 80.95% and 79.22%, respectively, suggesting that serum NT-proBNP level after PCI had certain predictive value for short-term prognosis of patients. CONCLUSION: Serum NT-proBNP level in elderly AMI patients after PCI has a good ability to predict the short-term prognosis of patients. Comprehensive consideration of the number of stents inserted, the presence of stroke, the presence of reflow and age and other factors to strengthen the monitoring of NT-proBNP level is helpful to prevent and control the occurrence of MACE, so as to improve the prognosis of patients.