Left ventricular pseudoaneurysm is a type of rare and lethal mechanical complication derived from rupture of the ventricular free wall but enclosed by the adherent pericardium or scar tissue. We present a rare case of a massive pseudoaneurysm with a large thrombotic burden. Echocardiography had a pivot role on early diagnosis of the pseudoaneurysm allowing for appropriate downstream diagnostic testing. Cardiac magnetic resonance confirmed a large pseudoaneurysm. Furthermore, late gadolinium enhancement imaging demonstrated large thrombotic burden within the pseudoaneurysm. Due to eminent risk of rupture and danger of an embolic event our patient underwent a successful ventricular aneurysectomy. The defect was closed with a 5cm patch of bovine pericardium. An echocardiogram day 6 post-op showed an intact patch repair with no residual pseudoaneurysm.