Ischemic ocular syndrome (IOS) is caused by stenosis of carotid artery. Proliferative retinopathy is one of the signs and can lead to misdiagnosis with diabetic retinopathy. IOS must be considered in case of proliferative retinopathy asymmetric and refractory to laser treatment. Carotid endarterectomy in patients with IOS with no neurologic manifestations remains controversy. This paper reported a patient with IOS simulating diabetic retinopathy and treated with endarterectomy.