Smokers experience cigarette cravings in response to both imaginal and in vivo cigarette cues, and some studies suggest that the magnitude of this reactivity relates to difficulty quitting. Few studies, however, have systematically examined these two paradigms head-to-head. To this end, the authors exposed 225 smokers to imaginal and in vivo smoking cues and measured craving reactions. Results indicated that both imaginal and in vivo smoking cues increased craving. The magnitude of imaginal and in vivo reactions were statistically comparable and were moderately correlated. In vivo, but not imaginal, reactivity was related to duration of previous quits, particularly in men. Findings suggest that although both paradigms induce craving, the in vivo reactivity paradigm may be, at least in men, more effective for predicting smoking cessation failure.