Arrhythmogenic right ventricular dysplasia (ARVD) is a cardiomyopathy of unknown etiology responsible for 20% of cases of sudden death in young adults secondary to arrhythmia. It is characterized histologically by fatty or fibro-fatty infiltration of the right ventricular myocardium. Diagnostic criteria have been proposed for diagnosing ARVD. Imaging, especially MRI, plays an important role. MR imaging must be performed using cardiac gating, and should include both cine-MR sequences for evaluation of segmental and global right ventricular function or any morphological change of the right ventricular shape, and anatomic sequences to detect fatty or fibro-fatty infiltration of the right ventricular myocardium.