The effects of alcohol intake and cigarette smoking on blood pressure among male workers of a chemical mamnufacturing industry in Yamaguchi Prefecture were investigated. An increase in blood pressure was related to not only the habit of alcohol intake over 29 ml per day but also the alcohol intake over a couple of times per week and below 29 ml per day. On the contrary, a vely low drinking group, which took alcohol ”sometimes”, had a tendency of a decrease in pressure. Moreover, an increase in rGTP was also observed in the groups of the alcohol intake a couple of times per week, below 29 ml per day and over 29 ml pel day. Cigarette smoking was associated with both effects, an increase in blood pressure of the group below 39 years old and a decrease in blood pressure of the groups from 40 to 49 years old and above 50years old. These results suggested that it was reasonable to use alcohol intake below 29 ml per day as a crucial point when the effect of alcohol on blood pressure investigated, and also the factor of age was very important for the investigation of the correlation between cigarette smoking and blood pressure.