Effective adjuvant treatment for recurrent respiratory papillomatosis (RRP) is at present limited to alpha-interferon, which may have significant side effects including rebound growth of papillomata following its withdrawal, is given by injection and is expensive. High dose cimetidine is known to have immunomodulatory side effects and has been reported as a useful treatment for cutaneous warts. We report a case of very advanced RRP with tracheo-bronchial-pulmonary involvement treated with adjuvant cimetidine at a dose of 40 mg/kg for 4 months. The patient enjoyed a remarkable improvement in her clinical condition following treatment. The literature regarding cimetidine treatment for cutaneous warts is reviewed.