Teamwork is crucial to organizational success and commitment to teams is an important predictor of team-related behaviors. However, theorists and researchers have typically assumed that commitment levels are generally stable within-persons, increasing or decreasing as a result of substantial organizational changes. This position is at odds with the evidence of systematic and regular intraindividual fluctuations in personal attributes and workplace behaviors. We draw upon affective events theory to present a model explaining how certain events and dispositions produce vacillations in affective reactions which, in turn, are likely to create within-person variation in affective commitment to teams (WPVCteams). We further propose that WPVCteams enhances prediction and explanation of intraindividual fluctuations in work behavior and, interindividually, moderates the relationship between level of commitment and behavior.