Introduction: Pseudoaneurysm of the left ventricle is a severe com- plication of myocardial infarction that results from a free cardiac wall rupture that is contained by the pericardium, thrombus, or adhesions. Most patients with a cardiac pseudoaneurysm will display symptoms of dyspnea or chest pain, but 10% of patients can be asymptomatic. Trans- thoracic Doppler color flow imaging is a suitable starting diagnostic method for diagnosing a pseudoaneurysm of the left ventricle. Cardiac magnetic resonance is an excellent complementary method for identify- ing this cardiac entity. Case description: A patient in heart failure was admitted to receive intensive care therapy. An electrocardiogram showed anterolateral ST elevation and two-dimensional echocardiogram [2DE] posterolateral akinesis of the left ventricle. After a satisfactory in-hospital course he was discharged without any apparent complication. Six months later he was referred for new evaluation due to heart failure symptoms. A 2DE revealed a pseudoaneurysm along the left ventricular lateral wall. A cardiac magnetic resonance confirmed a pseudoaneurysm contained by the pericardium. Late gadolinium-enhanced imaging demonstrated a transmural lateral myocardial infarction with marked delayed enhancement of the pericardium that forms the wall of the pseudoaneurysm. Results and conclusions: Early surgical intervention is recommended for a pseudoaneurysm of the left ventricle because of its tendency to rupture. Most patients do well after surgical repair, except for that requiring concomitant mitral valve replacement. However, the long-term outcomes of patients with a pseudoaneurysm not treated with surgery appear to be relatively benign, with a very low risk of fatal rupture. Therefore, a con- servative approach may be considered in these patients that should include chronic anticoagulation therapy because of a high risk of ischemic stroke. Take-home message: Transthoracic echocardiography is an accep- table starting diagnostic method in patients having a pseudoaneurysm. Cardiac magnetic resonance has been increasingly used as a non-invasive diagnostic method.