Impulsivity is associated with smoking, difficulties quitting smoking, and approach tendencies toward cigarette stimuli among adolescents. We examined the effects of impulsivity on (a) the association between approach tendencies and adolescents’ smoking status and (b) the effectiveness of Cognitive Bias Modification (CBM), a smoking cessation intervention focused on changing approach tendencies, among adolescent smokers. We conducted a secondary analysis of evidence from 2 previous published studies: Study 1: a cross-sectional study comparing impulsivity and approach tendencies between adolescent smokers (n = 67) and nonsmokers (n = 58); Study 2: a treatment study that randomized 60 adolescent smokers to receive either CBM or sham training. Impulsivity was measured using the Barratt Impulsiveness Scale (BIS) and the Experiential Discounting Task (EDT). We found higher impulsivity, as determined by the BIS but not the EDT, increased adolescents’ odds of being smokers. We observed that the interaction between EDT and approach tendencies also significantly predicted smoking status, however post hoc comparisons were not significant. Adolescents with higher BIS scores receiving CBM had increased odds of being abstinent at the end of treatment, but we found no association between EDT and treatment outcome. Our findings suggest that approach-bias modification (a form of CBM) may be more effective in impulsive adolescent smokers. Differences in findings for BIS and EDT highlight the complexity of the construct of impulsivity. Future studies with larger samples are needed to further disentangle the effects of different aspects of impulsivity on smoking behaviors and cessation outcomes among youth.