HISTORY AND CLINICAL FINDINGS A 62-year-old woman was admitted because of sudden onset of increasingly severe pain in the left lower leg and foot. She also reported having had diarrhoea for the past few days. INVESTIGATIONS Physical examination revealed a cold and pale left leg below the knee joint. Peripheral sensory and motor functions were normal. While femoral and popliteal arterial pulses were normally palpable, foot pulses were not felt. Magnetic resonance angiography of the pelvic and leg arteries showed an embolic occlusion of the left popliteal artery extending to the arteries of the lower leg. DIAGNOSIS, TREATMENT AND COURSE Because of the acute embolic occlusion of the deep femoral and popliteal arteries an embolectomy of the deep and superficial femoral arteries was performed. The source of the emboli had been a free-floating thrombus in the descending aorta. Subsequently a persistent fever and leukocytosis occurred which had been cause by a septic splenic infarction. A conventional splenectomy was done. The postoperative was protracted, because of the development of a pancreatic fistula, which responded to treatment. Anticoagulation treatment started. The patient was finally discharged after more than five weeks. CONCLUSION After urgent surgical treatment of an acute peripheral arterial occlusion its cause needs to be identified. Transthoracic echocardiography, computed tomography and magnetic resonance angiography are the methods of choice. If there is a floating aortic thrombus further embolizations, including septic splenic emboli may occur.