Systemic right ventricle (sRV) dysfunction is frequent in patients with congenitally corrected transposition of great arteries (cc-TGA) and those with dextro-transposition of great arteries (D-TGA) after Mustard/Senning operations. This condition should be identified promptly. We aimed to compare echocardiographic parameters with cardiac magnetic resonance (CMR)-derived parameters in patients with sRV and to evaluate their correlation with clinical variables and exercise capacity. Patients with cc-TGA and D-TGA after Mustard/Senning who underwent standard and advanced (speckle tracking and 3D) echocardiography and CMR (including feature-speckle tracking) were included. Clinical and imaging parameters were collected. Echocardiographic-derived right ventricle end-diastolic area and end-systolic area correlated with 3D echocardiographic-derived right ventricle end-diastolic and end-systolic volume (r=0.6, p=0.006 and r=0.8, p=0.002). 3D ejection fraction (EF) correlated with fractional area change and tricuspid annular plane systolic excursion (TAPSE) (r=0.8, p=0.001 and r=0.7, p=0.03). sRV global longitudinal strain (GLS) correlated with systemic atrial strain (sAS) (r=-0.6, p=0.01). CMR-derived EF correlated with CMR-derived GLS both endocardial and myocardial (r=-0.7, p=0.007 and r=-0.6, p=0.005). sRV areas as assessed by echo correlated with CMR-derived volumes (r=0.9, p=0.0001 for diastole and r=0.8, p=0.0001 for systole). Similarly, a correlation was found between sRV echo-derived GLS and CMR-derived GLS, both endocardial and myocardial (r=0.8, p=0.001 and r=0.7, p=0.01). The only imaging parameter that correlated with peak oxygen consumption was sAS (r=0.55, p=0.04). When comparing cc-TGA and D-TGA, the former showed better GLS-derived values as assessed by CMR (CMR-derived right ventricle endocardial longitudinal strain -23.2% versus -17.2%, p=0.002; CMR-derived right ventricle myocardial longitudinal strain -21.2% versus -16.7%; p=0.05), bigger systemic atrial area (20.2 cm2/m2 versus 8.4 cm2/m2, p=0.005) and higher TAPSE values (16.2 mm versus 12.2 mm, p=0.04). Echocardiography is valid to screen for sRV dilatation and function and to guide the timing for CMR. The investigation of atrial deformation imaging may help to better understand diastolic function. Patients with cc-TGA show better cardiac function compared to patients after atrial switch. Further investigations are needed to identify imaging parameters linked to exercise capacity.