This paper reports on the relationship between the stressfulness of the social environment, smoking and mortality rates for malignant neoplasms of the respiratory system and chronic obstructive pulmonary disease (COPD). A macro-social approach was employed with the 50 states of the United States serving as the units of analysis. A 'State Stress Index' was computed using stressful events in 15 categories (divorce rate, business failures, natural disasters, etc.). Smoking behavior was measured by percentage smokers and the average cigarette sales per capita. Mortality rates for lung cancer and COPD were standardized by age. The percent population living in metropolitan areas, black, below poverty line, and with less than high school education were included as controls in the multiple regression analysis. The results show that populations that experience higher levels of stressful events smoke more heavily and eventually experience higher mortality from lung cancer and COPD. These relationships are robust: they are replicated for different time periods, for different measures of the independent and dependent variables, and with different analytic methods. The pattern of findings is consistent with a 'health behavior' model of stress in which populations under stress engage in behavior which is extremely inimical to health.