It has been reported that angiotensin converting enzyme inhibitor (ACE-I) elicits dry cough more frequently in women than in men. This study was designed to evaluate whether airway cough receptors are more sensitive in women than in men. Cough threshold to inhaled tartaric acid was measured in 33 men and 29 women. In non-atopic and non-smoking subjects, geometric mean value of cough threshold in women was 10.0 (GSEM, 1.29) %, which was significantly (p less than 0.02) lower than that in men, 22.5 (GSEM, 1.30) %. In non-atopic men, the cough threshold was significantly (p less than 0.05) lower in smokers (9.3 (GSEM, 1.57) %) than in non-smokers. In non-smoking women, the cough threshold was significantly (p less than 0.02) lower in atopic subjects (4.2 (GSEM, 1.33) %) than in non-atopic subjects. These results demonstrated that airway cough receptors may be more sensitive in women, smoking men and atopic women.