Epidemiologic evidence points to gender-based differences in incidence, risk, histology, and pathogenesis of certain lung diseases in women as compared with men. Gender influences not only physiological differences, but also the social, economic, and cultural context in which men and women coexist. Central to these differences is the role of sex hormones, which may contribute to the pathogenesis of disease or serve as protective factors. This paper seeks to review the role of gender in major areas of pulmonary disease and explore the mechanisms that may underlie gender differences in asthma, chronic obstructive pulmonary disease and mycobacterial disease (tuberculosis and Mycobacterium avium intracellulare infection), on lung cancer.