We report a case of branch retinal vein occlusion in a 28-year-old woman that revealed Takayasu's arteritis. Somatic examination showed humeral blood pressure asymmetry and an abdominal murmur; a biological inflammatory syndrome was noted. Abdominal aortography showed marked stenosis of the superior mesenteric artery. Three of the six diagnostic criteria of Takayasu's arteritis were present in our patient, sufficing to make the diagnosis. This is the first case reported of branch retinal vein occlusion revealing Takayasu's arteritis. It is to be added to the List of atypical initial manifestations of Takayasu's arteritis such as anterior ischemic optic neuropathy. Branch retinal vein occlusion is a rare enough occurrence in a 28-year-old patient to warrant further clinical investigation.