In a combined sample of more than 2600 smokers, immediate postcessation craving is shown to be prospectively associated with smokers' ability to maintain abstinence. Relapse is strikingly rapid among those reporting high levels of craving following cessation. More than 32% of those with high craving scores relapsed within 1 week of cessation. In contrast, fewer than 15% of those with low craving relapsed in the first week (p < .001). Our findings provide a warrant for an increased research effort designed to provide a better understanding of the factors that control following smoking cessation and the processes by which craving influences smoking relapse.