The study of two cases of young patients with renal transplants who, successively and a few months after the procedure, presented a thrombophlebitis of the lower extremities (with or without pulmonary embolism), then an acute coronary insufficiency, without any encouraging or triggering factor, raises the hypothesis that this is not a mere coincidence. In fact, in the literature, numerous cardiovascular risk factors) inherent in complicated chronic renal failure, dialysis, steroid therapy and immuno-suppressive treatment (Azathioprime, under these circumstances) were demonstrated. In addition, abnormalities of the platelets aggregation, hemostasis and fibrinolysis, were at the origin of thrombo-embolic accidents. Besides any specific cardiovascular risk factor or any obvious biological anomaly, there is still a predisposition of patients with renal transplants, to arterial as well as venous thrombo-embolic accidents.