Fibromuscular dysplasia is a rare cause of stroke affecting mostly young females. It is characterized by the typical "string of beads" sign located mostly bilaterally in the midcervical portion of the carotid or vertebral arteries. We present the uncommon case of borderzone hemispheric infarction in a man with isolated unilateral fibromuscular dysplasia affecting continuously the distal extracranial and proximal intracranial portion of the left internal carotid artery leading to distal hypoperfusion and ischemia.