The case of a patient with acute occlusion of the right renal artery due to an embolus is described. Using transoesophageal echocardiography, the left atrial appendage could be identified as the source of embolism. Twenty hours after the onset of symptoms, the embolus could be successfully dissolved with an intra-arterial low-dose infusion of recombinant tissue-type plasminogen activator (10 mg loading dose, 20 mg continuous infusion within 12 h).