Objective: To evaluate the immediate effects of prone position ventilation (PPV) on right ventricular-pulmonary arterial coupling (RV-PA) and right heart function in patients with acute respiratory distress syndrome (ARDS) complicated by shock using transesophageal echocardiography (TEE), and to analyze its relationship with prognosis. Methods: A total of 110 patients with ARDS complicated by shock who received PPV were enrolled as subjects. For all patients, TEE was used to monitor right heart function indicators before PPV (supine position) and 1 hour after PPV. These indicators included tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RVFAC), and pulmonary artery systolic pressure (PASP). The TAPSE/PASP ratio was calculated to assess RV-PA coupling. Hemodynamic parameters, oxygenation indices before and after treatment, and 28-day mortality were also recorded. Results: At 1 hour after PPV, the patients' oxygenation index (PaO?/FiO?) improved (P<0.05). Right heart function indicators RVFAC and TAPSE increased (P<0.05), while PASP and right ventricular myocardial performance index (RMPI) decreased (P<0.05). The TAPSE/PASP ratio markedly increased (P<0.05). Multivariate Logistic regression analysis demonstrated that an increased TAPSE/PASP ratio and a decreased RMPI following PPV were independent predictors of 28-day all-cause mortality (P<0.05). Conclusion: PPV can immediately improve right heart function and RV-PA coupling in ARDS patients with shock. The TAPSE/PASP ratio monitored by TEE can serve as an important indicator for assessing the hemodynamic effects of PPV and predicting patient prognosis.