Echocardiographic demonstration of right ventricular thrombosis is relatively common in pulmonary embolism. There are also reports of right ventricular thrombi in patients affected by right myocardial infarction or dilated cardiomyopathy. In arrhythmogenic right ventricular cardiomyopathy single or multiple aneurysms are often present in the right ventricular free wall. These hypoakinetic areas represent a site for potential development of thrombi especially in advanced disease states. In the literature a single case of a patient affected by arrhythmogenic right ventricular cardiomyopathy with right heart failure and atrial and ventricular thrombi is reported. We report a case of arrhythmogenic right ventricular cardiomyopathy with a right ventricular thrombus located inside a single apical aneurysm in the presence of normal right ventricular systolic function.