The methanol extract of Drymaria cordata Willd. was investigated for its effect on a cough model induced by sulfur dioxide gas in mice. It exhibited significant antitussive activity when compared with the control in a dose-dependent manner. The antitussive activity of the extract was comparable to that of codeine phosphate, a prototype antitussive agent. The D. cordata extract (100, 200, 400 mg/kg) showed 11.6%, 31.6% and 51.5% inhibition of cough with respect to the control group.