Early diagnosis of cardiac involvement in boys with Duchenne muscular dystrophy (DMD) allows for timely therapy. The aim of this study was to assess the association between native T1 in the right ventricle (RV) and cardiac involvement as marked by decreased left ventricular (LV) or RV ejection fraction (EF). Healthy boys (N=10) and boys with DMD (N=16) underwent 3T cardiac MR using motion-corrected gradient-MOLLI T1-mapping, a clinically routine protocol. RV-T1 did not correlate with LVEF or RVEF. Longer native LV-T1 was associated with lower LVEF. Based on this data, native RV-T1 does not provide insight to cardiac involvement in DMD.