Classical teaching suggests that placement of a tracheostomy tube through the second or third tracheal rings will safeguard the innominate artery in the majority of patients. A tracheotomy was performed on ten fresh, adult cadavers through a vertical incision in the second and third tracheal rings. A series of measurements was made evaluating the relationship of the innominate artery to the tracheostomy tube and to laryngotracheal structures. In every dissection, some part of the tracheostomy tube cuff or tip was found to be adjacent to the innominate artery. We conclude that, contrary to general belief, placement of the tracheotomy incision at the second and third tracheal rings will not in and of itself protect the innominate artery from rupture.