1. Coughing was induced in ten healthy subjects with various threshold concentrations of nebulized citric acid. The citric acid aerosol method of cough induction proved a reliable and reproducible tool for assessing the cough threshold in an individual. The subjects were retested after consumption of 1 ml of ethanol/kg body weight. Coughing was significantly suppressed in nine of the ten subjects. 2. The marked suppression of the cough reflex by the moderate amounts of ethanol used in this study provides confirmatory evidence for the suspected causal links between ethanol abuse and certain pulmonary infections caused by aspiration.