Impulsivity is a core process underlying addictive behaviors, including nonpharmacological addictive behaviors such as problem gambling. Although considerable attention has been given to the investigation of delay discounting within the context of addiction-related behaviors, relatively little research has examined the relationship between discounting and individual variables, such as race/ethnicity. The purpose of this study was to compare discounting rates in the three most prevalent racial/ethnic groups in the United States: Whites, African Americans, and Hispanics. The study was conducted with 315 problem gamblers. Participants completed a delay-discounting questionnaire involving choices between a smaller amount of money delivered immediately and a larger amount delivered later. A hyperbolic discounting function estimated delay-discounting rates based on participants' indifference points obtained via the questionnaires. Results showed significant effects of race/ethnicity on delay discounting. White gamblers discounted delayed money at lower rates than African Americans and Hispanics, even after controlling for confounding variables. These data suggest that among individuals who develop problem gambling, Whites are less impulsive than African Americans and Hispanics, at least in terms of choosing between delayed and immediate reinforcers. These results have implications for evaluating the onset and treatment of addictive disorders from a health-disparities perspective.