Background and aimsQuitting smoking is the most potent way to reduce the health risks associated with smoking cigarettes, and public health objectives in the United States include dramatic increases in the proportion of smokers making a serious quit attempt each year. The US Centers for Disease Control and Prevention (CDC) has, since 2000, set as its Healthy People 2020 objective to encourage 80% of smokers to make a serious quit attempt per year. This study assessed the trend in quit attempts from 2009 to 2014. DesignWe examined the percentage of US smokers making a serious quit attempt each year from 2009 to 2014 from the repeating cross-sectional National Health Interview Survey (NHIS). SettingUnited States. ParticipantsThe number of qualifying respondents per year ranged from 5748 in 2010 to 7219 in 2012, with a total of 40362 respondents included in the analysis. MeasurementsRespondents were deemed to have made a serious quit attempt if they were either current smokers who reported that they stopped smoking for more than 1day in the past 12months because they were trying to quit smoking, or reported being former smokers (smoked 100+ cigarettes life-time, but now not smoking) who quit in the past year. FindingsAnalyses of trends from 2009 to 2014 showed an overall linear increase in quit attempts [odds ratio (OR)=1.02, 95% confidence interval (CI)=1.01-1.04, P=0.0075], but also a quadratic trend (OR=1.01, 95% CI=1.00-1.02, P=0.0189). ConclusionsThe proportion of US smokers making a serious quit attempt has increased since 2009, due to an upward trend since 2011. The 2014 serious quit attempt rate was 55.0%. These rates are still below the Healthy People 2020 objective of 80% of smokers making a serious quit attempt per year.