INTRODUCTION: Right ventricular (RV) size and function in Duchenne muscular dystrophy (DMD) have not been well described. Using cardiac magnetic resonance (CMR) imaging we describe the relationship of RV and left ventricular (LV) size and function in a large DMD cohort. METHODS: Latest CMR scans of 272 patients consecutively seen at a single tertiary referral center (2011-2014) with skeletal muscle biopsy confirmed DMD were included. 1.5 and 3 Tesla CMR scanners were used. Biventricular ejection fraction (EF), end-diastolic volume index (EDVI), mass and mass index were compared across categories of LVEF. RESULTS: Mean age was 13.5 ± 4.9 years. 71% had normal (≥ 55%) LVEF while mild (EF 45-54%), moderate (EF 30-44%), and severe LV dysfunction (EF <30%) was present in 20%, 6% and 3% respectively. The correlation between RVEF and LVEF was weak. Even in patients with severe LV dysfunction, RVEF (49.7% ± 12.9%) was relatively preserved. There were no significant differences in RVEDVI and RV mass index across categories of LV function. CONCLUSION: In a large DMD cohort, RVEF was relatively preserved and RV size was preserved across categories of LV dysfunction.