The complex extract and the polysaccharide isolated from the roots of marsh mallow were tested for antitussive activity in unanaesthetized cats of both sexes. Cough was elicited by mechanical stimulation of laryngopharyngeal and tracheobronchial mucous area of the respiratory system with a Nylon fibre (diameter 0.35 mm). Cough was evaluated on the basis of the changes in lateral tracheal pressure. The polysaccharide and the complex extract were administered p.o. in a dose of 50 and 100 mg/kg b.w., respectively. The efficiency of the mentioned compounds was compared with the cough-suppressing effect of drugs belonging to the non-narcotic antitussics. The results of the experiments showed that administration of the polysaccharide led to a statistically significant decrease of the number of cough efforts both from laryngopharyngeal and tracheobronchial areas of the the respiratory system. The polysaccharide in a dose of 50 mg/kg b.w. was as effective in inhibition of the cough reflex as Sirupus Althaeae in a dose of 1000 mg/kg b.w. and more effective than prenoxdiazine in a dose of 30 mg/kg b.w. However, the cough-suppressing effect of the polysaccharide was lower than that of dropropizine. The extract was less effective than the polysaccharide.