Smokers who wish to quit may refrain from doing so if they expect to experience more stress after haven given up. We test if stress-related expectations about smoking cessation are associated with quit attempts and abstinence among smokers who are motivated to quit. The study included 1809 daily smokers in Denmark in 2011-2013. Stress-related expectations (do you think you will be more, less or equally stressed as a non-smoker?) were measured at baseline. Quit attempts, 30-day point prevalence abstinence and prolonged abstinence (defined as having been abstinent since baseline), were measured after 3, 8 and 14 months. We found that the association between expecting to be more stressed if giving up smoking differed between participants who had previously attempted to quit and those who had not: In participants who previously attempted to quit (47%), expecting to be more stressed was associated with significantly lower odds of abstinence compared to smokers who expected the same or a lower level of stress (odds ratios were 0.49 (95% CI: 0.31-0.79) for 30-day abstinence and was 0.28 (95% CI: 0.08-0.99) for prolonged abstinence). In participants who had not previously attempted to quit, expectations about stress were not associated with abstinence. Results indicate that expectations about stress in relation to smoking cessation are an important determinant of cessation in smokers who previously attempted to quit. Addressing stress and how to handle stressful situations may increase the likelihood of a successful quit attempt.