This paper reports population-based secular trends in smoking prevalence and tobacco exposure among smokers. The Minnesota Heart Survey (MHS) assessed smoking in probability samples in the seven-county Minneapolis-St. Paul metropolitan area. Five surveys were conducted in 1980-1982, 1985-1987, 1990-1992, 1995-1997, and 2000-2002 using similar sampling strategies and consistent protocols. Participants were metropolitan area residents of Minnesota, aged 25-74 years, with the addition of 75-84-year-olds in the last three surveys. In men, age-adjusted self-reported prevalence of current smoking steadily declined from 32.9% in 1980-1982, to 23.0% in 1995-1997, and to 20.6% in 2000-2002. In women, self-reported smoking was 31.8% in 1980-1982, 18.5% in 1995-1997, and 19.5% in the latest survey. Age-adjusted self-reported quantity of cigarettes consumed among smokers declined over the same period. Changes from 1995-1997 to 2000-2002 were not significant. Compared with Whites, Black participants had higher levels of smoking and later onset of the decline in smoking prevalence. A decline in smoking prevalence seems to have leveled off or reversed between the two most recent survey periods (1995-1997 through 2000-2002). Focus on smoking cessation should continue, especially in the subpopulation that smokes more than the majority.