A 38-year-old man presented with ptosis, miosis, facial pain and hypoesthesia in the ipsilateral ophthalmic division of the trigeminal nerve. Brain magnetic resonance imaging and magnetic resonance angiography showed fusiform dilation of the cavernous portion of the left carotid artery. A diagnosis of Raeder's syndrome (RS) was made. Carbamazepine selectively relieved the facial pain but the partial Horner syndrome persisted. Our case adds dolichoectasia of the intracavernous internal carotid artery to the list of causes of RS.