OBJECTIVE: To express the increased risk from smoking in terms of 'blood pressure' so that hypertensive smokers are motivated into quitting. METHODS: Mortality risks of smokers were compared with nonsmokers in a large worker cohort in Taiwan (n = 23 755 with a 17-year follow-up) for all-cause and for cardiovascular diseases. The blood pressure equivalence of smoking was then identified by the difference in mortality risks between smokers and nonsmokers. RESULTS: Some interaction between hypertension and smoking was found to be synergistic. When hypertension and smoking co-existed, the all-cause mortality outcome [relative risk (RR) = 4.25] was larger than the sum or product of each individual risk for hypertension (RR = 2.16) or for smoking (RR = 1.97). The excess mortality risks of smoking for smokers were converted into a 'blood pressure equivalence'. The results demonstrate that the addition of smoking was similar to an increase of mortality risk approximately equivalent to an increase in blood pressure of 40 mmHg. CONCLUSIONS: Smoking cessation in hypertensive patients could provide a reduction of mortality risks similar to a permanent reduction of 40 mmHg in blood pressure, over and above any antihypertensive medications. Appreciating this relationship enables physicians to bridge the clinical disconnection and motivates hypertensive smokers to seek smoking cessation. The use of a 'blood pressure equivalence of smoking' can link the two separate risk factors and may lead to a paradigm shift in overcoming an existing clinical challenge.