40 patients suffering from chronic urticaria were randomly treated with either Terfenadine or Astemizole. The treatment period was 8 days after a 4 day wash out phase with placebo. The intensity of the symptoms was quantified and daily recorded by the patients. Both antihistamines influenced significantly the intensity of the pruritus and the flares. With the used study design and dosage slight superiority of Astemizole over Terfenadine could be observed. Neither Astemizole nor Terfenadine showed sedation side effects. The average amount of the sedation symptom scores was during the therapy phase on the same level as during the placebo phase.