This study examines motivations to quit smoking within the theoretical context of self-theories (Dweck, 2000). It investigates whether self-theories play a significant predictive role in motivating adults to quit smoking. A convenience sample of 197 adult current smokers and ex-smokers in northeast Ohio completed on line or paper versions of the Smoking Questionnaire, an instrument which included the 6-item Fagerstrom Test of Nicotine Dependence, 3-items from the Self-Theory of Intelligence Self-Form for Adults, and 23 items constructed by the researcher. Descriptive analyses indicate that the sample was 66% female, 77% white, 83% college educated, and of varied ages and incomes. Stepwise logistic regression analyses reveal 4 predictors of smoking cessation success: self-theory of smoking, the presence of other smokers in the household, annual household income, and strength of intention (motivation) to stop smoking. Logistic regression analyses also indicate that self-theory of smoking and perceived helpfulness of nicotine replacement therapy are statistically significantly predictive of strength of intention (motivation) to stop smoking. Self-theory of intelligence was not a significant predictor of smoking cessation motivation or behavior. Data indicate that self-theory of smoking and self-theory of intelligence are independent and domain specific in this sample. This research indicates that self-theories play a significant role in smoking cessation and that self-theories of smoking are as potent as nicotine replacement therapy in motivating individuals to stop smoking. This research has important implications for cessation program planners and health educators and many implications for additional research on the role of self-theories in health behavior change. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]