The authors report the case of a patient with a serious recurrence of pulmonary embolism with echocardiographic evidence of a floating serpentine thrombus of the right atrium. The outcome was rapidly satisfactory with disappearance of signs of acute cor pulmonale and lysis of the right atrial thrombus after infusion of two thrombolytic agents: Rt PA and streptokinase. There is no evidence in the literature to indicate that one form of treatment, i.e. surgical thrombectomy or thrombolysis, is markedly superior to the other. Thrombolysis appears to be a useful alternative to surgery. The use of Rt PA and of the combination of two thrombolytics has not been published previously and merits confirmation.