The aim of this paper was to evaluate the effect of one month of treatment with different dosages of glycerol on experimental endolymphatic hydrops produced by obliteration of endolymphatic sac and duct through an extradural approach. Forty-two guinea pigs were used. The animals, divided into six groups, received 0.5-2 gr/kg body weight of the drug per day for one month. The activity of glycerol was determined by statistical analysis of volumetric changes of scala media. Glycerol demonstrated the effect of reducing endolymphatic hydrops. The decrease in hydrops was influenced by the dosage suggesting a stria metabolic response.