We report a case of spontaneous iliac occlusion in a 44-year-old male patient after long-distance running. Atherogenic risk factors like hypertension, diabetes, hypercholesterolemia and smoking were missing. Spontaneous iliac occlusion is extremely rare and only a few cases have been documented. Angiography showed occlusion of the left iliac artery with collateral flow via the obturator artery to the common femoral artery. Thrombectomy was performed but reocclusion occurred. An iliacofemoral bypass, arterial lysis and bypass thrombectomy was necessary within a few months. At the last follow-up visit two years afterwards the patient was symptom-free. This case indicates that exercise-dependent blood flow disturbances in long-distance-runners could produce changes of the intima.