Although aortic valve replacement (AVR) and mitral valve replacement (MVR) are the most commonly performed prosthetic valve replacement operations, it is unclear whether clinical outcomes of paravalvular leakage (PVL) after MVR or AVR are different. It was hypothesized that clinical outcomes of PVL after AVR would be more favorable than after MVR because the pressure gradient is much larger in PVL occurring at the mitral position, which happens at the systolic phase, than at the aortic valve. Over a 12-year period, 82 patients with PVL were identified. After excluding patients who required immediate surgical repair for severe symptoms, patients with Behet disease or infective endocarditis, and those with PVL involving both valves, 54 remaining patients (21 women, mean age 56 ± 14 years, 23 AVRs) with mild to moderate leakage constituted the study population. The end points were cardiac death, all-cause mortality, repeat surgery, and urgent admission for heart failure. During a median follow-up period of 35 months, there were 27 events, including 23 repeated surgeries, 2 cardiac deaths, 1 noncardiac death, and 1 admission for heart failure. Cox regression analysis revealed that the valve location of PVL was the only independent clinical predictor of event-free survival. The estimated 8-year event-free survival rate was significantly higher in patients with PVL after AVR than those after MVR (70 ± 12% vs 16 ± 8%, p <0.0001). In conclusion, PVL after AVR demonstrated more favorable long-term clinical outcomes compared to that after MVR. In patients who develop PVL after AVR, repeat surgery may be deferred. However, in patients with PVL after MVR, more aggressive therapeutic approaches should be considered.