Severe unilateral cases of Menière's disease can be successfully treated with ototoxic antibiotics. Among them gentamicin sulfate gives the safest results. With the aid of a small syringe this antibiotic is introduced into the external auditory canal 5 times/ day. From there it reaches the middle ear through a ventilating tube by using a Politzer bag. Gentamicin then penetrates the round and oval windows, where it influences inner ear function. Of 92 patients treated during the past 20 years, more than 90% have had no further attacks after therapy.