Pseudoaneurysms of the ulnar artery are very rare and usually are caused by penetrating injury. In this paper, we present a 27year old male soldier with pseudoaneurysm of the left ulnar artery which caused both motor and sensory deficits of the left ulnar nerve as a result of a pressure effect by the mass. He was treated by surgical resection of the pseudoaneurysm and direct repair of the ulnar artery and he gained a full recovery of the neurological deficit within two months.