We present a case of 38-year-old patient with a large left ventricular aneurysm, which was filled by the thrombus, separated from the rest of the left ventricle by a hyperdensive area. After careful invasive and non-invasive assessment, the patient was selected for conservative treatment. Patients after myocardial infarction, especially with low ejection fraction and young age, should undergo a complete noninvasive diagnostic procedures and a cardiac catheterization in order to establish indications for surgical treatment. The described case is an example of the difficulty in final selection of the patient to a surgical treatment.