The impact of reducing smoking initiation, increasing smoking cessation, and combination approaches on life expectancy, deaths averted, and life-years gained in a birth cohort of 50,000 persons and in the state population (3.6 million) were analyzed. A 60% reduction in initiation of smoking in adolescents would increase life expectancy by 0.42 years. Over the next 100 years, there would be an additional 18,000 years of life for a birth cohort and an additional 675,000 years of life for the state's population. The reduction in mortality, however, would not begin before 35 years, and only 25% of the benefit would occur in the next 70 years. An increase in smoking cessation would have a smaller impact that would occur sooner. Maximum reduction in mortality could be achieved by reducing initiation and increasing cessation at all ages, but a reduction in mortality would not occur for several decades.