Background: Ambient air pollution is a leading risk factor for cardiovascular diseases. No study has investigated the association between fine particulate matter (PM2.5) exposure and prognosis of patients undergoing right ventricle-pulmonary (RV-PA) artery conduit surgery. We hypothesized that PM2.5 can lead to stenosis of the conduit by stimulating inflammatory response in the conduit lumen. Methods: From 2013 to 2020, patients with six complicated congenital heart defects and had undergone RV-PA operation in Beijing Fuwai Hospital were selected. Four conduit materials were used: bovine jugular vein graft (BJV), pulmonary homograft (PHG), aortic homograft (AHG), and handmade tri-leaflet expanded polytetrafluoroethylene (ePTFE) conduit. Telephone interviews were used to confirm the patients' postoperative addresses. The monthly averages of PM2.5 concentrations were obtained from the ChinaHighPM2.5 dataset using patients' places of residence. By comparing findings of echocardiography performed prior to patients' return to their residence and during re-examination, we defined the trans-conduit peak velocity increase of ≥1.5 m/s as the study endpoint. Results: 232 patients were included in the study. Logistic analysis identified the female gender to be a protective factor against conduit velocity increase (Odd Ratio (OR) 0.270 (95% confidential interval (CI): 0.094-0.780), P = 0.016). Compared with BJV conduits, homografts (AHGs and PHGs) (0.052 (95% CI: 0.005-0.558), P = 0.015) and ePTFE conduits (0.009 (95% CI: 0.002-0.054), P <0.001) were protective factors. The cumulative monthly PM2.5 concentration (unit 10μg/m3) was a risk factor (1.014 (95% CI: 1.001-1.026), P = 0.028). Winter experience was a risk factor (1.971 (95% CI: 1.021-3.804, P = 0.043). In the subgroup analysis, Spearman correlation analysis identified BJV conduits (r = 0.680, P <0.001), PHGs (r = 0.559, P = 0.020), AHGs (r = 0.745, P = 0.021) had medium-to-high positive correlations between the cumulative PM2.5 concentration and conduit velocity change. For ePTFE, the correlation was weak and not significant (r = 0.222, P = 0.073). Conclusion: Postoperative PM2.5 exposure affects the patency of biologic prosthetic conduits, especially the xenograft. The ePTFE conduit velocity increase is not associated with PM2.5 exposure which is a suitable material for patients living in high pollutant concentration areas.