We examined racial/ethnic variations in the use of nicotine replacement therapy (NRT) and quit ratios among Caucasian, African American, Asian, and Latino lifetime smokers ages 25 to 44 years. We conducted cross-sectional analyses using data from individuals (n = 27,031) screened for enrollment in the Collaborative Study of the Genetics of Nicotine Dependence. Participants were randomly sampled from three Midwestern metropolitan areas using Health Maintenance Organization membership lists in Detroit, MI and Minneapolis, MN and a driver's license registry in St. Louis, MO from March 2003 to August 2005. A telephone survey collected information on smoking history, previous quit attempts, and sociodemographic characteristics. Among lifetime smokers (n = 9,216), univariate analysis indicated that African Americans (22%) and Latinos (22%) were significantly less likely to report having ever used NRT for smoking cessation than Caucasians (31%). Asians (22%) also reported lower rates of using NRT than Caucasians, but this difference was marginally significant (P = 0.06). These disparities persisted in multivariate analysis for African Americans [adjusted odds ratio (OR), 0.76; 95% confidence interval (95% CI), 0.63-0.91; P < 0.01] but not for Latinos (adjusted OR, 0.76; 95% CI, 0.54-1.06; P = 0.11) or Asians (adjusted OR, 0.98; 95% CI, 0.60-1.60; P = 0.95). As measured by the quit ratio, African Americans (35%) were less likely to have quit smoking than Caucasians (52%). This disparity persisted in multivariate logistic regression (adjusted OR, 0.66; 95% CI, 0.56-0.78; P < 0.001). Asian and Latino smokers were as likely as Caucasians to report smoking cessation. Future prospective studies are needed to assess whether lower utilization of cessation treatments such as NRT contribute to the observed disparity in quit ratios for African Americans.