Papilloma is the common benign tumor of the larynx and the incidence of its malignant change was variable. The authors recently experienced 2 cases of squamous cell carcinoma of the larynx which were considered to be transformed from laryngeal papilloma. Case 1 : A 58 years old male patient visited O.P.D. of Department of Otolaryngology of Busan National University Hospital, because of hoarseness for 3 years on May 13th, 1980. At that time, local finding of indirect laryngoscopy revealed whitish hypertrophic papillomatous mass on both vocal cords and anterior commissure, and dirty gray white pseudomembrane on left aryepiglottic fold, and the result of biopsy was squamous cell papilloma. So the laryngeal papilloma was removed under suspension laryngoscopy and then he had no specific treatment in spite of being recommended 5-FU topical spray. On March 5th, 1981, he visited O.P.D. again because of progressive exacerbation of hoarseness with mild dyspnea and histopathological finding was revealed squamous cell carcinoma of the larynx. Seven days later from that day, he visited emergency room due to severe dyspnea, and emergency tracheostomy was performed on sitting position. On April 7th, 1981, total laryngectomy was performed successfully and postoperative irradiation therapy was recommended. Case 2 : A 47 years old male patient visited out O.P.D. because of hoarseness for 5 years on Sep. 27th, 1978. At that time, local finding of indirect laryngoscopy revealed papillomatous mass on left vocal cord and left ventricle and result of biopsy was squamous cell papilloma. So he had been treated with 11 times removal of papilloma, topical spray of 5-FU and estrogen for 3 years, but the papilloma had been recurred. On Sep. 19th, 1981, he visited O.P.D. because of severe dyspnea and emergency tracheostomy and biopsy was performed. The result of biopsy was squamous cell carcinoma of larynx and total laryngectomy was performed sucessfully.