Dextromethorphan, the most widely used cough suppressant in the U.S.A., was compared with codeine, the traditional European antitussive, in a double-blind, crossover trial using both an objective and subjective assessment of efficacy in sixteen patients with chronic, stable cough. Both preparations, at a dose of 20 mg, were similarly effective in reducing cough frequency. Dextromethorphan lowered cough intensity to a greater degree than codeine (p less than 0.0008) and was considered the better antitussive by the majority of patients (p less than 0.001). In view of its lack of side-effects, its safety even in overdose and its non-narcotic status, the increasing trend in Europe to use dextromethorphan as a substitute for codeine in the treatment of cough is to be welcomed.