abstract–The deodorizing effect in cases of foetor ex ore of a new mouthwash based on the principle of ascorbic acid oxidation has been investigated by means of a gas chromatographic method. The preparation was given to ten of 22 subjects whose saliva upon shorttime incubation and gas chromatographic head space analysis had shown rapid formation of malodorous sulfur volatiles. Dosage was one tablet four times a day for 1 d. Saliva was sampled the morning before and the morning after the day the preparation was used. The analysis showed total elimination or considerable reduction of the odorous compounds found in head space of saliva sampled in the morning the day after the treatment. The mechanism of this deodorizing effect is briefly discusse