Computed tomography (CT) offers a unique method of displaying the anatomy of laryngeal cancer. Asymmetrical contours of the thyroid cartilages were found as a normal variant. Marked asymmetry may indicate buckling of the cartilage which could contribute to acute airway obstruction following radiation therapy. A low density, soft tissue plane medial to the thyroid cartilages may prove valuable in evaluating cartilaginous involvement with tumor. CT should make a significant contribution to more accurate planning of radiation therapy portals by showing the relationship of lymphatic spread to the primary tumors.