The current study assessed relationships between the ratio of early diastolic tricuspid inflow to tricuspid lateral annular velocity (tricuspid E/e′) and right ventricular (RV) function in children after tetralogy of Fallot (TOF) repair. The RV function of 25 asymptomatic children with surgically repaired TOF (age 3.3 ± 2.0 years) was assessed by echocardiography and cardiac catheterization. Right ventricular end-diastolic pressure and volume (RVEDP and RVEDV), systolic pressure, and ejection fraction, as well as mean pulmonary arterial pressure, mean right atrial pressure (RAP), and the severity of both pulmonary regurgitation (PR) and tricuspid regurgitation (TR) were assessed in terms of the contribution to tricuspid E/e′. Univariate analysis discovered a relationship between tricuspid E/e′ and RVEDV (R ² = 0172), pressure half-time of PR (PR-PHT) (R ² = 0.173), and TR grade (R ² = 0.145) (p < 0.01 for each). After multivariate adjustment, PR-PHT was significantly associated with tricuspid E/e′ (β = 0.210; p < 0.001). Tricuspid E/e′ was not significantly associated with RVEDP or RAP. In conclusion, tricuspid E/e′ does not indicate RV diastolic function but reflects the severity of PR in asymptomatic children after TOF repair.