The antiallergic and decongestive effects of the common cold preparation Balkis was tested by rhinomanometry in human volunteers usually suffering from allergic rhinitis after oral treatment. The nasal irritation in these patients was induced by administration of the specific allergen. This kind of test is especially appropriate for the control of drugs in cases of ordinary colds, as the test conditions are reproducible in symptomatically similar cases. The rhinomanometrical control of the respiratory resistance was carried out before and after an allergenic exposal as well as before and after administration of Balkis and allergenic exposal in 30 patients (17 females, 13 males; 9-49 years old). It is shown that Balkis had a good to satisfactory antiallergic effect in 67% of all cases. In 33% of the cases the antiallergic effect was not evident. This result confirms objectively the good antiallergic effect of this common cold preparation by oral administration. Balkis was well tolerated in all of the 30 patients. The symptoms of slight fatigue which appeared in 1/3 of all cases were only transitory.