Prolapse of the laryngeal ventricle is a rare lesion, which is seen mainly in male. In most instances, the disease appears unilaterally. In April 1977, the authors experienced prolapse of the laryngeal ventricle in a 54 years old female, who was treated successfully by laryngofissure. She had a history which was hoarseness of 5 years duration and dyspnea of 9 months duration. Laryngoscopy revealed polypoid mass beneath either the false cord, that was enough large to obstruct the glottis partially and not to be visualized the vocal cord at phonation or respiration. The polypoid mass originated from either ventricle was removed by laryngofissure after tracheostomy. Repeated histological studies revealed chronic inflammation. The postoperative course was satisfactory showing disappearance of dyspnea and the polypoid mass and remaining only slight hoarseness. Reporting own case, the authors reviewed the literature.