Rationale: Despite the decades-long emphasis on withdrawal in leading models of addiction, the causal mechanisms driving smoking withdrawal effects are not well known. This gap in the knowledge base has stalled theory and treatment development for smoking dependence. Objectives: As cognitive factors have been largely neglected as predictors of withdrawal, the current study sought to examine how smokers' abstinence-related expectancies relate to withdrawal symptomatology. Methods: Adult smokers (N = 180; ≥10 cigarettes/day) participated in two counterbalanced experimental sessions involving either 16 h of abstinence or smoking as usual. At baseline, participants completed three withdrawal-related scales of the Smoking Abstinence Questionnaire (Withdrawal, Optimistic Outcomes, and Weight Gain scales), a self-report measure of smokers' abstinence-related expectancies. During experimental sessions, participants completed a number of instruments that covered the range of smoking withdrawal effects (i.e., negative affect, urge/craving to smoke, diminished positive affect, concentration difficulty, hunger, and physiological symptoms). Results: Even after controlling for the influence of demographic characteristics and cigarette dependence, smokers' abstinence-related expectancies were meaningful predictors of abstinence-induced changes in various withdrawal symptoms (mean adjusted standardized β = 0.22). Stronger expectancies for withdrawal and weight gain predicted more severe withdrawal effects, whereas stronger expectancies for optimistic outcomes predicted less severe withdrawal effects. Conclusions: These findings are consistent with the notion that expectancies actively shape future experience and are the first to support the suggestion that smokers' abstinence-related expectancies may be causal agents of withdrawal symptomatology. Future research is required to more conclusively determine whether abstinence-related expectancies mold withdrawal effects. © 2013 Springer-Verlag Berlin Heidelberg.