The personality trait of sensation seeking has been positively associated with risk of smoking initiation and level of tobacco use. However, its role in smoking cessation is much less established. This study examined the association between sensation seeking and smoking cessation among 236 heavy social drinkers participating in a clinical trial testing the efficacy of incorporating brief alcohol intervention into smoking cessation treatment. As hypothesized, higher sensation seeking predicted reduced odds of abstinence from smoking as well as greater alcohol use over 26 weeks of follow-up. Sensation seeking also significantly interacted with age, having a protective influence on smoking outcomes among the youngest participants and an increasingly negative effect on smoking outcomes with greater age. Compliance with nicotine replacement therapy and use of smoking cessation strategies (e.g., planning for high risk situations, thinking about the benefits of quitting, avoiding smoking situations) were negatively associated with sensation seeking and accounted for most of the main effect of sensation seeking on smoking outcomes. Findings suggest (a) that smokers high in sensation seeking may require a specific emphasis on treatment compliance and behavioral rehearsal of cessation strategies, and (b) that the significance of sensation seeking for smoking cessation may change with increasing age.