Adult, male smokers were randomly assigned to be nicotine abstinent for 12 h (n=10) or to smoke normally for the same period of time (n=10). Performance on a modified version of the Stroop (1935) color-naming task, where subjects named the color of ink in which each of a series of words was written, showed that abstinent smokers took significantly longer to color-name words related to cigarette smoking (e.g., Lighter) than to color-name neutral control words (e.g., Pennant). Non-abstinent smokers showed a significant difference in the opposite direction. These results suggest that nicotine abstinence decreases the ability to ignore the meaning of smoking-related information. This finding supports the hypothesis that abstinence produces a content-specific shift in attentional focus. The present pattern of results cannot be explained by a general decrease in cognitive function due to nicotine abstinence.