Two cross-sectional surveys of the entire membership of the Fukuoka Prefecture Medical Association were conducted in 1983 and 1990 using a self-administered questionnaire, and respondents were registered as the study cohort. In this investigation the trend of the actual prevalence of smoking among physicians and the relationship between their smoking cessation and living habits were studied. A decline in the actual prevalence of smoking was demonstrated among the 2,656 subjects who responded to both surveys (2,543 men and 113 women). To examine any relationship between lifestyle variables and smoking cessation after 1983, those who were smokers in 1983 (1,099 men and 7 women, total 1,106) were divided into two groups, according to whether or not they still smoked in 1990. Subjects who quit smoking accounted for a larger proportion of those physicians with any of the following life-style variables: earlier bedtimes, unawareness of mental stress, greater consumption of fresh vegetables and fruit, and less coffee consumption. Further observation of the relationship between smoking cessation and changes in lifestyle variables showed that there were more who quit smoking among those who became employed physicians, had an increase of the body mass index (BMI) and began to be aware of mental stress. These results suggested that, for physicians who smoked, it is a possibility that smoking was an important way of coping with stress, and thus pointed to the need to take mental-health measures to help physicians to stop smoking.