Left ventricular thrombosis is relatively common after acute myocardial infarction, especially in the anterior site, and represents a possible cause of potentially lethal peripheral embolization 1. Therefore, several studies have been performed in order to assess the efficacy of different antithrombotic drugs in resolving the detected thrombi or reducing their embolic potential. Fibrinolytic agents appear effective in this regard: in the majority of cases, they produce complete lysis and resolution of the thrombi. However, this treatment may itself cause embolic complications by producing a rapid fragmentation of thrombus and the subsequent emission of disrupted portions of the intracardiac mass into the systemic vascular bed . This dramatic effect of thrombolysis has suggested the possibility that even the standard treatment of acute myocardial infarction with fibrinolysis implies a danger of embolization in those patients in whom a left ventricular thrombus may be present either from a previous myocardial infarction or from a very early thrombus development. However, this hypothesis has not yet been confirmed by direct observation. We report the case of a patient with a first acute anterior myocardial infarction, in whom the thrombolytic treatment induced lysis and embolization from a left ventricular thrombus present in an aneurysmatic dilatation of the infero-posterior wall due to a previous inferior myocardial infarction.