Oxatomide was evaluated in a double-blind study of 35 patients with chronic urticaria. For 5 weeks patients received at random either 30 mg oxatomide b.i.d. or a placebo. Oxatomide significantly reduced not only the duration of the attacks but also the severity of erythema, lesions and itching. This lower level of suffering was clearly reflected by a diminished need for additional antiallergic medication. The overall response to treatment was rated excellent or good in 72% of the oxatomide-treated patients against only 23% of the controls which is a significant difference. Sleepiness was reported in 1 patient of each group.