Cervical rib is a congenital phenomenon that usually occurs in association with upper-limb neurovascular symptoms. The presence of a cervical rib displaces the great vessels that cross the thoracic outlet superiorly and proceed into the neck. We report an unusual case of iatrogenic hemorrhage during a tracheostomy in a patient whose right subclavian artery had been displaced by a cervical rib. Our aim is to alert surgeons to the hidden risks of this phenomenon.