We present the case of right ventricular thrombus formation associated with a right ventricular infarct secondary to a proximal right coronary artery thrombus, which was not evident on transthoracic echocardiography but detected on both delayed gadolinium enhanced magnetic resonance imaging and microsphere contrast echocardiography. The diagnosis of right ventricular thrombosis altered the decision to place an implantable cardiac defibrillator in this patient. Anticoagulation with warfarin resulted in resolution of the thrombus. This case highlights the utility of multimodality imaging in the detection and follow-up of right ventricular thrombus in the setting of right ventricular myocardial infarction, and the effectiveness of anticoagulation therapy. © 2011.