The personality traits of harm avoidance (HA), novelty seeking (NS), and reward dependence (RD), as measured by the Tridimensional Personality Questionnaire (TPQ), have been linked to smoking behavior. The extent to which these traits are associated with smoking withdrawal and cessation outcome is unclear. We sought to address this question among 131 treatment-seeking smokers who were randomly assigned to either a smoking cessation treatment (four 30-min behavioral counseling sessions) or a control condition. We found that HA was positively associated with baseline depressive symptoms, baseline negative affect, and post-quit withdrawal, and negatively associated with positive affect at both baseline and post-quit. Additionally, we found that smokers with higher HA scores were more likely to be abstinent. NS was negatively associated with post-quit positive affect and positively associated with post-quit negative affect and withdrawal. RD was not found to be related to any outcome measures. Our findings suggest that, despite experiencing greater baseline and post-quit negative affect, smokers higher in trait harm avoidance are more likely to quit smoking. The treatment and theoretical ramifications of these findings are discussed.