This study examined the effects of abstinence from smoking, of smoking history, and of nicotine administration on visual attention (2-Letter Search Task), verbal information processing (Logical Reasoning Task), and working memory (N-Back Tasks). Fourteen smokers, 15 ex-smokers, and 9 never-smokers took part. All subjects participated in a training session (when smokers had been smoking ad libitum) and in two subsequent test sessions after administration of 4 mg nicotine gum or placebo, respectively. Smokers were 12-h abstinent when they received gum. An effect of acute nicotine administration (independent of smoking history) was seen only with respect to reaction time on the 2-Letter Search Task. Working memory performance was related to smoking history (smokers performed most poorly and never-smokers best). The Logical Reasoning Task showed no effects of either acute or chronic nicotine exposure. The findings indicate that nicotine may influence focusing of attention in smokers as well as nonsmokers, and that trait-like differences in some cognitive domains, such as working memory, may be either long-term effects or etiological factors related to smoking.