Background: The myocardial kinetic energy (KE) and its association with pulmonary regurgitation (PR) have yet to be investigated in repaired tetralogy of Fallot (rTOF) patients. Purpose: To evaluate the adaptation of myocardial KE in rTOF patients by tissue phase mapping (TPM). Study Type: Prospective. Population: A total of 49 rTOF patients (23 AE 5 years old; male = 32), 47 normal controls (22 AE 1 year old; male = 29). Field Strength/Sequence: 3-T/2D dark-blood three-directional velocity-encoded gradient-echo sequence. Assessment: Left and right ventricle (LV, RV) myocardial KE in radial (KE r ), circumferential (KE ø ), longitudinal (KE z ) directions. The proportions of KE in each direction to the sum of all KE (KE røz ): %KE r , %KE ø , %KE z . PR fraction. Statistical Test: Student's t test, multivariable regression. Statistical significance: P < 0.05. Results: In rTOF group, LV KE z remained normal in systole (P = 0.565) and diastole (P = 0.210), whereas diastolic LV %KE z (62% AE 14% vs. 72% AE 7%) and systolic LV %KE ø (9% AE 6% vs. 20% AE 7%) were significantly decreased. The KE r and %KE r of both ventricles significantly increased in the rTOF group (RV in diastole: 6 AE 3 vs. 3 AE 1 μJ and 54% AE 13% vs. 27% AE 7%). The rTOF group exhibited significantly higher RV/LV ratios of %KE r (systole: 1.3 AE 0.3 vs. 1.0 AE 0.3) and %KE ø (systole: 1.6 AE 0.8 vs. 1.0 AE 0.3) and significantly lower ratios of %KE z in systole (0.7 AE 0.2 vs. 1.0 AE 0.1) and diastole (0.5 AE 0.2 vs. 0.9 AE 0.1). In multivariable regression analysis, the RV peak systolic KE røz , RV systolic KE z , and LV diastolic %KE ø were independently associated with PR fraction in the rTOF group (adjusted R 2 = 0.479). Data Conclusion: In rTOF patients, the adaptation of the KE proportion occurred earlier than that of the KE amplitude, and the biventricular balance of %KE was disrupted. PR may cause differential KE adaptation in RV and LV. TPM-derived KE may be useful in investigation of myocardial adaptation in rTOF patients.