Research has shown that outcome expectancies predict smoking behavior, and expectancy challenge interventions can reduce smoking. This study tested the hypothesis that supplementing expectancy challenge with a behavioral activation intervention promoting increased exposure to alternative reinforcers would help increase motivation to quit and induce actual quit attempts within the following month among young adult smokers. Smokers, aged 18–35 (N = 159, of whom 93 provided one-month follow-up data) and not required to be interested in quitting at the point of enrollment, were randomized to (a) the combined cognitive-behavioral intervention, (b) a cognitive-only expectancy challenge, or (c) a neutral reading (control) task. There were no significant between-group effects on motivation, but the conditions differed significantly in likelihood of leading to a quit attempt. Post hoc comparisons showed the combined condition participants (52 % of completers) to be significantly more likely than control group participants (25 %) to make a quit attempt, with the cognitive-only group (43 %) intermediate and not significantly different from the other conditions. These data provide preliminary evidence of utility for the brief cognitive-behavioral intervention in promoting smoking cessation attempts; more research is needed to test various possible explanations of how and for whom the intervention is effective, as well as whether it would significantly exceed expectancy challenge alone in larger samples.