Smoking-cessation messages usually emphasize the costs of continuing to smoke (loss-framed). However, prospect theory suggests that messages that instead emphasize the benefits of quitting smoking (gain-framed) could be more effective than loss-framed messages because smoking cessation is likely viewed as a cancer-prevention behavior with a certain rather than a risky outcome. In this study, smokers at public events read brochures containing brief gain- or loss-framed smoking-cessation messages. The influence of framing was moderated by participants' need for cognition (NFC). Individuals lower in NFC had greater intention to quit after reading a gain-framed message than after reading a loss-framed message a finding consistent with our predictions whereas framing did not affect the persuasiveness of messages among people higher in NFC.