We describe a case of spontaneous coronary artery dissection in a 38-year-old woman presenting with anterior myocardial infarction who was initially treated with thrombolysis. During the administration of thrombolytics the clinical symptoms and the electrocardiogram (ECG) deteriorated. Coronary angiography revealed a major dissection in the proximal left descending coronary artery. A spontaneous dissection was hypothesized to have extended by thrombolytic-induced bleeding into the dissected vessel wall. Therefore, we advocate that, especially in young female patients presenting with an acute myocardial infarction and without cardiac risk factors, direct coronary angiography be considered, rather than thrombolytic therapy, in order to decide for the optimal therapeutic strategy.