Introduction: Racial and gender disparities for smoking cessation might be accounted for by differences in expectancies for tobacco interventions, but few studies have investigated such differences or their relationships with motivation to quit and abstinence self-efficacy. Methods: In this cross-sectional study, 673 smokers (African American n = 443, 65.8%; women n = 222, 33.0%) under criminal justice supervision enrolled in a clinical smoking cessation trial in which all received bupropion and half received counseling. All participants completed pretreatment measures of expectancies for different tobacco interventions, motivation to quit, and abstinence self-efficacy. The indirect effects of race and gender on motivation to quit and abstinence self-efficacy through expectancies for different tobacco interventions were evaluated. Results: African Americans' stronger expectancies that behavioral interventions would be effective accounted for their greater motivation to quit and abstinence self-efficacy. Women's stronger expectancies for the effectiveness of pharmacotherapy accounted for their greater motivation to quit, whereas their stronger expectancies for the effectiveness of behavioral treatments accounted for their greater abstinence self-efficacy. Conclusions: Findings point to the mediating role of expectancies for treatment effectiveness and suggest the importance of exploring expectancies among African Americans and women as a way to augment motivation and self-efficacy. © The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved.