Primary myxofibrosarcoma of the heart is quite rare. We herein present the case of a 56-year-old man who presented with large obstructive myxofibrosarcoma of the right ventricle (RV), as assessed on multi-diagnostic imaging techniques (multidetector row computed tomography, magnetic resonance imaging and positron emission tomography). Most previous cases of cardiac myxofibrosarcoma have been reported in the left atrium and ventricle. In this report, we describe a very rare case of large obstructive myxofibrosarcoma of the RV.