Little is known about factors associated with smoking among the unemployed. This study estimated the prevalence of smoking and examined sociodemographic factors associated with current, former, and successful quitting among unemployed adults aged 18-64. Cross-sectional data on 13,480 participants in the 1998-1999 and 2001-2002 Tobacco Use Supplements to the Current Population Surveys were analyzed. Multivariate logistic regression analyses were used to examine factors associated with study outcomes (current vs. never, former vs. current, successful quitter vs. other former smoker). Among the unemployed, 35% were current smokers and 13% were former smokers. Of the former smokers, 81% quit successfully for at least 12 months. Participants with family incomes of less than US$25,000 were more likely than those with incomes of $50,000 or more to currently smoke (OR=2.13, 95% CI=1.85-2.46). Service workers and blue-collar workers were less likely than white-collar workers to report former smoking. Participants unemployed for 6 months or more were twice as likely as those unemployed for less than 6 months to quit successfully (OR=2.05, 95% CI=1.07-3.95). Unemployed blue-collar workers had a greater odds ratio of successfully quitting than white-collar workers (OR=1.83, 95% CI=1.17-2.87). Smoking rates were high among the unemployed, and quitting behaviors varied by sociodemographic factors and length of unemployment. Studies are needed to examine the feasibility of cessation interventions for the unemployed.