ABSTRACT The aim of the present study was to test potential models of smoking-related changes in mood and how these are moderated by personality (behavioral activation and inhibition systems). Three models yielding distinct predictions regarding mood changes associated with cues to smoking and effects of ingestion were identified: the negative reinforcement model, the appetitive-incentive model, and the incentive-sensitization model. Seventy participants provided baseline data on personality and mood, and subsequently monitored their smoking behavior over 48 hours using an event-contingent diary—eliciting reports of mood state immediately prior to, and after, each cigarette smoked. MANOVA and multilevel modeling indicated that mood (hedonic tone and energetic arousal) improved significantly (p<.001) from baseline to pre-smoking, but did not change from pre- to post-smoking, thereby supporting the incentive-sensitization model. Further multilevel analyses indicated that significant variability in hedonic tone was moderated by the behavioral activation system.