Marfan's syndrome is an autosomal dominant condition with a prevalence of 4 to 6:100,000, and classically comprises skeletal changes, ectopia lentis and cystic medial necrosis of the largest arteries. The latter leads to aneurysm formation, most often commencing at the aortic root, and is responsible for an average age at death of 32 years. We describe successful preservation of threatened renal function by renal autotransplantation, without concurrent aortic replacement, following dissection of the descending aorta in a patient with Marfan's syndrome.