Much research has shown that individuals exhibit an attentional bias to stimuli related to their current concerns or pathologies. Using the emotional Stroop task, we investigated attentional bias in smokers. Ninety-six smokers either abstained from smoking for 24 hr or smoked normally before color-naming smoking-related and neutral words. Both a blocked format (smoking and neutral words presented in separate blocks) and an unblocked format (smoking and neutral words presented in a mixed random sequence) were used. In the blocked format, abstinence caused an attentional bias to smoking-related stimuli, and the degree of attentional bias predicted the latency to the first cigarette of the morning. However, different results were obtained from the unblocked version of the task. We conclude that the emotional Stroop task is a useful tool to measure attentional bias in smokers and could be used in cessation studies.