We report a case of recurrent laryngeal papillomatosis which developed into laryngeal squamous cell carcinoma 11 years after the first diagnosis. Interestingly, we could identify HPV type 18 DNA in the carcinoma tissue using the polymerase chain reaction (PCR). Other known risk factors of irradiation, smoking, exposure to chemical agents, or a hereditary tendency to malignant tumours were not present in this case. Our finding suggests that HPV type 18 is another aetiological agent for laryngeal carcinoma.