We present a case of a 63-year-old patient referred to a cardiology consultation due to progressive symptoms of heart failure. He had a history of an inferior ST elevation acute myocardial infarction 6 years ago. Echocardiogram revealed a giant left ventricular aneurysm/pseudoaneurysm involving the inferior and inferolateral left ventricular walls, with a massive mural thrombus. Additional characterization was done by cardiac magnetic resonance, essential in establishing the diagnosis of pseudoaneurysm and to guide subsequent management. In this case, we discuss the differential diagnosis between aneurysm and pseudoaneurysm and highlight the role of non-invasive multimodality imaging.