Background. Since the 1980s, Brazil has implemented comprehensive tobacco control policies alongside major social changes, including improvements in education and reductions in poverty. These transformations contributed to a substantial decline in smoking prevalence and established Brazil as a global reference in tobacco control. However, the extent to which these changes have shaped recent mortality patterns and life expectancy across regions remains unknown. This study examines the contribution of smoking-related mortality to adult life expectancy in Brazil by sex and state from 2000 to 2023. Methods. Smoking-related mortality was estimated using the Peto-Lopez method. Changes in life expectancy at age 35 were decomposed by age and cause of death using the linear integral method. Results. Between 2000 and 2023, adult life expectancy at age 35 increased from 37.8 to 41.5 years among men and from 43.3 to 46.6 years among women. Among men, smoking-related mortality contributed 23.5% to this increase. States with the largest improvements, including Rio de Janeiro (36.4%) and Rio Grande do Sul (54.7%), showed the largest contributions from reductions in smoking-related mortality. Among women, increases in smoking-related mortality contributed negatively to changes in adult life expectancy (3.9%), driven by increased mortality after age 60. This negative contribution was observed in most states. Conclusion. Trends in smoking-related mortality, partly driven by tobacco control policies, have contributed to increases in life expectancy among men, with important differences across states. Addressing sex and regional disparities in smoking mortality will support gains in life expectancy.