INTRODUCTION: The impact of coexisting left-sided valvular heart disease (VHD) on clinical outcomes following tricuspid valve edge-to-edge repair (T-TEER) for tricuspid regurgitation (TR) remains unclear, particularly under real-world conditions. To evaluate the prevalence and prognostic impact of concomitant left-sided VHD in patients undergoing T-TEER. METHODS: This study included all patients undergoing T-TEER from the European Registry of Transcatheter Repair for Tricuspid Regurgitation (EuroTR; NCT06307262) with complete echocardiographic data on left-sided valve disease. Study endpoints included survival and heart failure hospitalizations (HFH) at 2 years, NYHA functional class, and TR reduction. RESULTS: Among a total of 1647 eligible patients, 95.8%, 35.6%, and 3.8% had ≥mild, moderate, and severe concomitant VHD, respectively. Moderate or higher VHD was associated with a significantly reduced 2-year survival (P < .001) and reduced 2-year HFH-free survival (P = .005). Multivariate regression analysis confirmed ≥ moderate VHD to be an independent predictor of mortality (hazard ratio 1.54, 95% CI 1.21-1.96, P < .001). Despite worse TR and NYHA functional class at baseline in patients with ≥moderate VHD, T-TEER was associated with a significant TR reduction (P < .001) and symptomatic improvement (P < .001). CONCLUSION: Concomitant left-sided VHD is common among patients undergoing T-TEER and is independently associated with worse survival and higher rates of HFH. Nevertheless, T-TEER provides meaningful symptomatic benefit and durable TR reduction in patients with and without VHD burden.