The authors report the case of tamponade without cardiac rupture 48 hours after a second course of intravenous thrombolytic therapy undertaken for unstable angina in laterobasal infarction in a 72 year old woman. The outcome after ultrasonic guided pericardiocentesis and surgical drainage (700 cc) was favourable. This is a rare complication of thrombolytic therapy (10 cases) and usually observed after anterior myocardial infarction.