Despite significant declines during the past 30 years, cigarette smoking among adults in the United States remains widespread, and year-to-year decreases in prevalence have been observed only intermittently in recent years. To assess progress made toward the Healthy People 2020 objective of reducing the proportion of U.S. adults who smoke cigarettes to ≤12% (objective TU-1.1),* this report provides the most recent national estimates of smoking prevalence among adults aged ≥18 years, based on data from the 2012 National Health Interview Survey (NHIS). The findings indicate that the proportion of U.S. adults who smoke cigarettes fell to 18.1% in 2012. Moreover, during 2005-2012, the percentage of ever smokers who quit increased significantly, from 50.7% to 55.0%, and the proportion of daily smokers who smoked ≥30 cigarettes per day (CPD) declined significantly, from 12.6% to 7.0%. Proven population-level interventions, including tobacco price increases, high-impact antitobacco mass media campaigns, comprehensive smoke-free laws, and barrier-free access to help quitting, are critical to decreasing cigarette smoking and reducing the health and economic burden of tobacco-related diseases in the United States.