R. Eisenberger's (1992) learned industriousness theory states that individuals display differing degrees of persistence depending on their history of reinforcement for effortful behavior. These differences may influence the development, maintenance, and cessation of addictive behaviors. In cross-sectional studies, E. P. Quinn, T. H. Brandon, and A. L. Copeland (1996) found that cigarette smokers were less persistent than nonsmokers, and R. A. Brown, C. W. Lejuez, C. W. Kahler, and D. R. Strong (2002) found that smokers who had previously abstained for 3 months were more persistent than those who had never quit. The present study extended these findings by using a prospective design. A pretreatment measure of task persistence (mirror tracing) completed by 144 smokers predicted sustained abstinence throughout 12 months of follow-up. Moreover, persistence predicted outcome independent of other significant predictors: gender, nicotine dependence, negative affect, and self-efficacy.