Background: Tricuspid regurgitation severity has recently gained attention as a prognostic predictor of outcome events in patients who have leftsided heart failure. This study sought to define the relationship between tricuspid regurgitation and outcome in patients with heart failure with reduced ejection fraction. Objective: To investigate the characteristics of tricuspid regurgitation by Doppler echocardiography in patients with heart failure and reduced ejection fraction. To explore the association between the severity of tricuspid regurgitation and short-term mortality and hospital readmission in the study patients. Methods: 116 heart failurereduced ejection fraction patients were enrolled in this study, followed up, and evaluated after 3 - 6 months. Results: 48.3% of patients have mild tricuspid regurgitation, 33.6% of patients have moderate tricuspid regurgitation, and 18.1% of patients have severe tricuspid regurgitation. 47 events (40.5%) occurred: 11 deaths (9.5%) and 38 readmissions (32.8%). A Kaplan - Meier curve showed that the survival rate of the severe tricuspid regurgitation group was significantly lower than the group with mild to moderate tricuspid regurgitation. A multivariate Cox regression model identified that tricuspid regurgitation severity was an independent predictor of 3-to-6-month mortality or readmission (HR 1.94; CI 95% 1.30 - 2.91). Conclusion: Tricuspid regurgitation severity was an independent predictor of reduced ejection fraction in patients with heart failure.