Increased mortality among smokers as compared to nonsmokers is well known. A 40-year longitudinal mortality study by Doll et al1 of 34,000 male British physicians from 1951 to 1991, in which smoking status was regularly ascertained, was reported in 1994. The cause of death was determined in > 90% of cases. The absolute all-cause mortality rate in middle-aged patients was twice as high among smokers as compared to nonsmokers, and life expectancy was 8 years shorter among continuing smokers as compared to lifelong nonsmokers. But if a smoker stopped smoking before the age of 35 years, the death rate for the rest of his life was indistinguishable from that of nonsmokers. A similar but progressively lesser effect was noted in successive age groups until groups ≥ 65 years old, for whom smoking cessation no longer caused a measurable effect on continued longevity.