The importance of identity in smoking cessation is increasingly becoming recognized by researchers. This study is the first in-depth longitudinal qualitative investigation of identity change processes among smokers who intend to quit. Participants' accounts of smoking, attempts to quit and sense of identity were explored over time to examine identity continuity and change. Ten smokers with a quit intention were interviewed three times, approximately 1 month apart, and approached for follow-up 2 years later. Data from 30 in-depth interviews were analyzed using the interpretative phenomenological analysis approach. Two themes of identity change processes are presented: "Identity transition makes it easier to quit" and "Identity conflict resolution is needed when quitting is unsuccessful or not attempted." Identity transition toward the identity of nonsmoker appeared to be facilitated by permeable identity boundaries, a continuous sense of identity, and a sense of mastery of quitting. Conflicted smoker identities were observed among participants who continued to smoke, along with barriers that appeared to prevent them from identifying with nonsmoking. Among these participants psychological (e.g. using downward comparisons with worse-off smokers) and behavioral strategies (e.g. hiding smoking from others) were seen that may serve to resolve identity conflict and protect a positive sense of identity. Our findings suggest that transition toward a nonsmoker identity may be necessary for successful quitting. Future research investigating ways to help smokers to perceive themselves increasingly as nonsmokers appears indicated.