We report a case of 43-year-old previously healthy male admitted to our hospital with symptoms of heart failure. Two-dimensional echocardiography demonstrated a previously undiagnosed dilated cardiomyopathy and massive left intraventricular thrombi. Because patient did not give consent for surgical thrombectomy, thrombolytic treatment with streptokinase was introduced. In the further course of hospitalization, ischaemic stroke was diagnosed despite the resolution of intracardiac thrombi observed on serial control echocardiography.