Epidemiological studies have demonstrated that cigarette smoking increases the incidence of myocardial infarction and sudden death. Psychological and physical stress, like smoking, activates the sympathetic adrenal medullary and pituitary-adrenal cortical systems. We therefore thought that the effects of stress and smoking together might increase the risk of cardiovascular disease. The seventeen-year Lebanese war was a source of real psychological stress. It was a very traumatic time for many citizens, forced to cope with the situation and its tragic consequences. We evaluated the effects of smoking and traumatic experiences during war using a study population of 46 Lebanese men aged between 28 and 45. We determined hemodynamic characteristics, such as heart rate and arterial blood pressure, and plasma indicators (cortisol and thromboxane concentrations). We found that smoking itself significantly increased all of these variables. The increase was larger, but not significantly so, in smokers who had experienced traumatic events during the war. This study suggests that preventive efforts should be directed at those groups with combinations of risk factors (e.g. smoking and stress) rather than at groups with one risk factor only. Accurate assessment of risk factors, their predictive value and their interactions are vital for any program of preventive measures.