In a double-blind randomized study 60 patients with either irritative cough due to seasonal respiratory disorders or chronic cough of any etiology were treated with either butamirate citrate linctus (Sinecod, Zyma) or with clobutinol syrup (Silomat, Boehringer, Ingelheim) for a period of 5 days at a dose regimen of 3 tablespoons daily. Efficacy was assessed based on the reduction of the severity as well as frequency of the cough and on the global opinion of the physician. Both groups showed highly significant improvements for the severity and frequency parameters (p less than 0.001), thus demonstrating the effectiveness of both treatments. No significant differences between groups were detected globally for the whole collective. For cough due to carcinomas (n = 14), however, a significantly better effect of butamirate on the frequency of cough (p = 0.026) was found which originated other significant differences in the global scores (p = 0.013) and in the physician's opinion (p = 0.026). Seven patients in both groups complained about side effects (mainly nausea and drowsiness).