Models of addiction have identified deficits in inhibitory control, or the ability to inhibit inappropriate or unwanted behaviors, as one factor in the development and maintenance of addictive behaviors. Current literature supports disruption of the prefrontal circuits that mediate reactive inhibitory control processes (i.e. inhibition in response to sudden, unplanned changes in environmental demands) in substance use disorders, however, the relationship between disorders of addiction, such as nicotine dependence, and planned inhibitory processes is unclear. The goal of the present study was to examine the extent to which reactive and planned inhibitory processes are differentially disrupted in nicotine dependent individuals. To this aim, we employed a novel stop signal task that explicitly separates planned and reactive inhibitory processes and assessed (1) group differences in task performance between smokers and non- smokers and (2) the relationship between task performance and smoking behaviors within the smoking group. We found significant differences in stop times for both trial between groups as well as within groups. Analyses of stopping behavior in the smoking group revealed an inverse correlation between stop times on planned stop trials and a measure of nicotine dependence derived from the Fagerstrom Test of Nicotine Dependence and, surprisingly, showed that greater daily average consumption of nicotine was inversely related to stop times for both trial types. Finally, we found that recency of the last cigarette smoked was unrelated to stopping behavior.