Cigarette smokers are known to be overrepresented among adults with Attention Deficit Hyperactivity Disorder (ADHD). To date, however, no attempt has been made to determine the extent to which a lifetime diagnosis of ADHD may be associated with smoking even in the absence of current symptomatology. We hypothesized that nicotine dependence and abstinence effects-especially effects relevant to ADHD symptomatology-would be more pronounced in adult ADHD smokers in comparison with those who reported childhood ADHD symptoms only. Results indicated that, in contrast to controls without ADHD symptomatology, both adult and childhood ADHD groups were significantly more likely to experience a number of nicotine withdrawal symptoms, including irritability and difficulty concentrating; in no instance did the ADHD groups differ from one another in this regard. Thus, studying people with childhood symptoms of ADHD, even in the absence of an adult diagnosis, may shed light on the known association between smoking and ADHD.